Spheroidal catalyst for olefin polymerization

ABSTRACT

A solid, spheroidal polymerization catalyst having a particle size distribution characterized by a Dm*/Dn of less than 3.0, the catalyst comprising a phosphinimine catalyst, a cocatalyst and a magnesium chloride support. A process for the polymerization of ethylene with one or more alpha olefin catalyzed by a solid, spheroidal polymerization catalyst having a particle size distribution characterized by a Dm*/Dn of less than 3.0, the catalyst comprising a phosphinimine catalyst, a cocatalyst and a magnesium chloride support.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This application is a divisional of U.S. application Ser. No.14/967,704, filed on Dec. 14, 2015, entitled “Spheroidal Catalyst forOlefin Polymerization”, which is herein incorporated by reference in itsentirety.

TECHNICAL FIELD

The present disclosure is directed to the use of solid, spheroidalolefin polymerization catalysts for the polymerization of ethylene withat least one alpha-olefin comonomer. The solid, spheroidal olefinpolymerization catalysts comprise a spheroidal MgCl₂ support, aphosphinimine catalyst and a cocatalyst.

BACKGROUND ART

The use of solid, spheroidal catalysts for use in the heterogeneouspolymerization of ethylene is well known. The prior art catalysts aretypically based on metallocene catalysts or Ziegler-Natta catalysts andare supported on spheroidal magnesium chloride supports. Methods forpreparing such catalysts include methods which rely on emulsion, spraydrying, and controlled precipitation techniques. These catalysts mayprovide for improved product morphology and bulk density.

U.S. Pat. Nos. 5,106,804 and 5,439,995 describe the use of a spheroidalcatalyst based on a zirconocene single site catalyst supported onspheroidal magnesium chloride particles. Pre-polymerization, followed bypolymerization using these catalysts gave polymer with good morphology.The spheroidal magnesium chloride support particles are made in thepresence of a non-reactive electron donor compound such as a non-proticether compound. For further descriptions of spheroidal magnesiumchloride particles and their use as supports see CA Pat. Nos. 1,189,053;2,036,767 and 2,092,769.

DETAILED DESCRIPTION OF DISCLOSURE

We have found that the morphology of the magnesium chloride particles isessentially unchanged when the non-reactive electron donor issubstantially removed, and that such particles can be used to makesolid, spheroidal catalysts based on phosphinimine catalysts. The solid,spheroidal phosphinimine based catalysts give polyethylene polymerhaving good morphology, even in the absence of a pre-polymerizationstep.

Provided is a spheroidal olefin polymerization catalyst having aparticle size distribution characterized by a Dm*/Dn of less than 3.0,wherein said catalyst comprises: a phosphinimine catalyst, a cocatalyst,and a spheroidal magnesium chloride support, wherein the magnesiumchloride support comprises particles with a mass average diameter Dm of5 to 100 μm, a particle size distribution characterized by a Dm/Dn ofless than 3.0, and comprises less than 2% by weight of an electron donorcompound.

Provided is a method of making a spheroidal olefin polymerizationcatalyst having a particle size distribution characterized by a Dm*/Dnof less than 3.0, wherein said method comprises: i) combining adialkylmagnesium compound with a non-protic ether, ii) combining theproduct of step i) with a source of chloride anion, iii) treating theproduct of step ii) to substantially remove the non-protic ether, iv)combining the product of step iii) with a phosphinimine catalyst and acocatalyst.

Provided is a process for polymerizing ethylene and at least onealpha-olefin to produce an ethylene copolymer, said process comprisingcontacting a spheroidal olefin polymerization catalyst with ethylene andat least one alpha-olefin in a polymerization reactor, wherein saidspheroidal olefin polymerization catalyst has a particle sizedistribution characterized by a Dm*/Dn of less than 3.0 and comprises: aphosphinimine catalyst, a cocatalyst, and a spheroidal magnesiumchloride support; wherein the magnesium chloride support comprisesparticles with a mass average diameter Dm of 5 to 100 μm, a particlesize distribution characterized by a Dm/Dn of less than 3.0, andcomprises less than 2% by weight of an electron donor compound.

Provided is a spheroidal ethylene copolymer comprising at least 75 wt %of ethylene units with the balance being alpha-olefin units, thepolyethylene having a density of from 0.910 g/cm³ to 0.936 g/cm³ and aparticle size distribution characterized by a Dm*/Dn of less than 3.0;wherein the polyethylene is made by polymerizing ethylene and at leastone alpha-olefin with a spheroidal olefin polymerization catalyst havinga particle size distribution characterized by a Dm*/Dn of less than 3.0,and comprising: a phosphinimine catalyst, a cocatalyst, and a spheroidalmagnesium chloride support; wherein the magnesium chloride supportcomprises particles with a mass average diameter Dm of 5 to 100 μm, aparticle size distribution characterized by a Dm/Dn of less than 3.0,and comprises less than 2% by weight of an electron donor compound.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an SEM micrograph of MgCl₂ support particles.

FIG. 2 shows a stereomicroscope picture of MgCl₂ support particles afterheat treatment.

FIG. 3A shows a stereomicroscope picture of olefin polymerizationcatalyst particles made according to the present disclosure.

FIG. 3B shows a stereomicroscope picture of olefin polymerizationcatalyst particles made according to the present disclosure.

FIG. 4A shows a stereomicroscope picture of olefin polymerizationcatalyst particles made according to the present disclosure.

FIG. 4B shows a stereomicroscope picture of olefin polymerizationcatalyst particles made according to the present disclosure.

FIG. 5A shows a stereomicroscope picture of ethylene copolymer particlesmade according to the present disclosure.

FIG. 5B shows a stereomicroscope picture of ethylene copolymer particlesmade according to the present disclosure.

FIG. 6A shows a stereomicroscope picture of ethylene copolymer particlesmade according to the present disclosure.

FIG. 6B shows a stereomicroscope picture of ethylene copolymer particlesmade according to the present disclosure.

FIG. 7 shows a stereomicroscope picture of ethylene copolymer particlesmade according to a comparative example.

FIG. 8 shows a stereomicroscope picture of ethylene copolymer particlesmade according to a comparative example.

BEST MODE FOR CARRYING OUT THE DISCLOSURE

The present disclosure provides solid spheroidal catalysts based on aphosphinimine catalyst which is supported on a magnesium chloridematrix. The catalyst polymerizes ethylene optionally with one or morealpha-olefins to give an ethylene (co)polymer having improved morphologyand bulk density.

By the term “spheroidal” it is meant that the particles will have aspheroidal shape defined by the fact that the long axis D of theparticle divided by the short axis d of the particle is ≤1.5, or ≤1.3,or when viewed under a stereomicroscope has a generally spherical shapeor when viewed with a scanning electron microscope (SEM) has a generallyspherical shape.

The solid, spheroidal catalyst of the present disclosure comprises aphosphinimine catalyst, a cocatalyst and a magnesium chloride support.

The solid catalyst is comprised of spheroidal (spherical like) particleswith a particle size distribution characterized by a Dm*/Dn of ≤3.0,where Dm* is the “relative” mass average diameter of the catalystparticles and Dn is the number average diameter of the catalystparticles.

In an embodiment of the disclosure, the spheroidal catalyst particleshave a Dm*/Dn of 2.5 or less. In an embodiment of the disclosure, thespheroidal catalyst particles have a Dm*/Dn of 2.0 or less. In anembodiment of the disclosure, the spheroidal catalyst particles have aDm*/Dn of 1.5 or less. In further embodiments of the disclosure, thespheroidal catalyst particles have a Dm*/Dn of from 1.0 to 3.0, or from1.0 to 2.75, or from 1.0 to 2.5, or from 1.0 to 2.0, or from 1.0 to 1.5.

In an embodiment of the disclosure, the solid spheroidal catalystparticles have a mass average diameter, Dm of from 5 to 100 micrometers(μm), or any narrower range within this range. In an embodiment of thedisclosure, the spheroidal catalyst particles have a Dm of from 5 to 75μm. In another embodiment of the disclosure, the spheroidal catalystparticles have a Dm of from 5 to 50 μm. In further embodiments of thedisclosure, the spheroidal catalyst particles have a Dm of from 5 to 40μm, or from 5 to 30 μm, or from 5 to 25 μm, or from 10 to 50 μm, or from10 to 40 μm, or from 10 to 30 μm.

The support used in the present disclosure consists essentially ofmagnesium chloride, wherein the magnesium chloride is in the form ofspheroidal particles having a mass average diameter Dm of between 10 and100 μm and a particle size distribution, defined as the mass averagediameter, Dm over the number average diameter, Dn of ≤3.0. Suchspheroidal magnesium chloride supports as well as their preparation arewell known in the art, as disclosed in CA Pat. No. 1,189,053 and U.S.Pat. No. 5,106,804. The magnesium chloride support may also containsmall amounts of chloride containing aluminum compounds, such as forexample, trichloroaluminum, and Grignard moieties such as Mg-carbonbonds, or compounds having Mg-carbon bonds.

In an embodiment of the disclosure, the magnesium chloride support willcontain substantially no Mg-carbon bonds.

The spheroidal magnesium chloride (MgCl₂) support is generally preparedby reacting a diorganomagnesium compound with an organic chloridecompound in the presence of a suitable electron-donating compound.Hence, during the formation of the magnesium chloride support anelectron-donor compound must be present to induce the formation of aspheroidal magnesium chloride support. Preferably, the electron-donorcompound is chosen from electron-donor compounds having moieties orfunctional groups which will not react with a diorganomagnesiumcompound's Mg-carbon bonds. Hence, electron donor compounds such aswater, alcohols, and phenols, are preferably avoided.

Without wishing to be bound by theory, the electron donor compound isbelieved to act as a complexing agent and not as a reactant, and helpsthe MgCl₂ particles form in a highly spheroidal and uniform shape.

The diorganomagnesium compound may be a dihydrocarbylmagnesium such asdialkylmagnesium or diarylmagnesium.

In an embodiment of the disclosure, a diorganomagnesium compound has thegeneral formula MgR^(a)R^(b) where R^(a) and R^(b) are eachindependently selected from C₁ to C₂₀ hydrocarbyl groups. In anotherembodiment of the disclosure, a diorganomagnesium compound has thegeneral formula MgR^(a)R^(b) where R^(a) and R^(b) are eachindependently selected from C₁ to C₈ hydrocarbyl groups.

Suitable dialkylmagnesium compounds include dibutylmagnesium (e.g.di-n-butylmagnesium), diisopropylmagnesium, dihexylmagnesium (e.g.di-n-hexylmagnesium), diethylmagnesium, propylbutylmagnesium (e.g.n-propyl-n-butylmagnesium), butylethylmagnesium (e.g.n-butyl-ethylmagnesium) and other compounds having the general formulaMgR^(a)R^(b) where R^(a) and R^(b) are each independently selected fromC₁ to C₈ linear or branched alkyl groups.

Diarylmagnesium compounds include for example diphenylmagnesium, andditolylmagnesium.

Diorganomagnesium compounds having alkylaryl groups are alsocontemplated for use with the current disclosure and include for exampledibenzylmagnesium.

In cases where the diorganomagnesium compound is not readily soluble inthe diluents of choice for the catalyst preparation, it may be desirableto add a solubilizing compound such as an organoaluminum or organozinccompound prior to use. Such compounds are discussed in, for example,U.S. Pat. Nos. 4,127,507 and 4,250,288. Alternatively, wherediorganomagnesium compounds provide solutions which are overly viscousin diluents of choice, solubilizers such as organoaluminum compounds ororganozinc compounds may be used to decrease the viscosity of thesolution.

In an embodiment of the disclosure, the diorganomagnesium compounds aretreated with a solubilizing agent (or viscosity improving agent) and areformulated as solutions in a suitable hydrocarbon solvent. Suchsolutions are commercially available from suppliers such as Albermarle,Akzo Nobel, etc. For example, diorganomagnesium compounds available inhydrocarbon solution include solutions of butylethylmagnesium ordibutylmagnesium which have been treated with an organoaluminum compoundto improve solubility and/or reduce solution viscosity.

The organic chloride compound is not specifically defined and can be anysuitable organic chloride compound, which is capable of providing anactive (i.e. reactive) chloride ion for reaction with an organomagnesiumbond. Preferably the chloride source will react spontaneously and fullywith the diorganomagnesium compound, but a chloride source whichrequires a transfer agent such as described in U.S. Pat. No. 6,031,056is also contemplated for use with the current disclosure.

In an embodiment of the disclosure, the organic chloride compound willbe an alkyl chloride having the formula R^(c)Cl, wherein R^(c) is a C₃to C₁₂ secondary or tertiary alkyl group.

In an embodiment of the disclosure, the molar ratio of the organicchloride compound to the diorganomagnesium compound used is during thepreparation of the spheroidal magnesium chloride support is from 1.5 to2.5.

In embodiments of the disclosure, the electron donor compound isselected from esters, thioethers, esters, sulfones, sulfoxides,secondary amides, tertiary amines, tertiary phosphines andphosphoramides.

In an embodiment of the disclosure, the electron-donor compound is anorganic electron donor compound (also known as a Lewis basic compound)and is preferably free of reactive hydrogen (i.e. “non-protic” or“aprotic”).

In an embodiment of the disclosure, the electron-donor compound is anon-protic organic electron donor compound.

In an embodiment of the disclosure, the electron-donor compound is anon-protic ether compound.

In an embodiment of the disclosure, the electron donor compound has lowcomplexing power, such as a cyclic or non-cyclic ether compound.

In an embodiment of the disclosure, the electron donor compound is anaprotic organic ether compound.

In an embodiment of the disclosure, the electron donor compound is annon-protic (i.e. aprotic) aprotic organic ether compound having theformula R¹⁰OR¹¹ where R¹⁰ and R¹¹ are the same or different alkyl groupshaving from 1 to 12 carbons atoms.

In an embodiment of the disclosure, the molar ratio of the electronicdonor compound to the diorganomagnesium compound used is during thepreparation of the spheroidal magnesium chloride support is from 0.01 to2. In further embodiments of the disclosure, the molar ratio of theelectronic donor compound to the diorganomagnesium compound used isduring the preparation of the spheroidal magnesium chloride support isfrom 0.01 to 1.5, or from 0.1 to 1.5, or from 0.1 to 1.2, or from 0.2 to0.8.

In an embodiment of the disclosure, the formation of the spheroidalmagnesium chloride support is carried out at from 0° C. to 100° C., orat from 5° C. to 80° C.

The reaction between the diorganomagnesium compound and the organicchloride compound which is carried out in the presence of the electrondonor compound is carried out in an inert liquid in which the resultingmagnesium chloride support is insoluble. Hence the reaction is aprecipitation reaction. Suitable inert liquids are liquid hydrocarbons.

In an embodiment of the disclosure, the spheroidal magnesium chloride(i.e. MgCl₂) support particles have a mass average diameter Dm of from 5to 100 micrometers (μm), or any narrower range within this range. In anembodiment of the disclosure, the spheroidal magnesium chloride supportparticles have a Dm of from 5 to 75 μm. In another embodiment of thedisclosure, the spheroidal magnesium chloride support particles have aDm of from 5 to 50 μm. In further embodiments of the disclosure, thespheroidal magnesium chloride support particles have a Dm of from 5 to40 μm, or from 5 to 30 μm, or from 5 to 25 μm, or from 10 to 50 μm, orfrom 10 to 40 μm, or from 10 to 30 μm.

In an embodiment of the disclosure, spheroidal MgCl₂ support particleshave a particle size distribution characterized by a Dm*/Dn of ≤3.0,where Dm* is the “relative” mass average diameter of the catalystparticles and Dn is the number average diameter of the catalystparticles.

In an embodiment of the disclosure, the spheroidal MgCl₂ supportparticles have a Dm*/Dn of 2.5 or less. In an embodiment of thedisclosure, the spheroidal MgCl₂ support particles have a Dm*/Dn of 2.0or less. In an embodiment of the disclosure, the spheroidal MgCl₂support particles have a Dm*/Dn or 1.5 or less. In further embodimentsof the disclosure, the spheroidal MgCl₂ support particles have a Dm*/Dnof from 1.0 to 3.0, or from 1.0 to 2.75, or from 1.0 to 2.5, or from 1.0to 2.0, or from 1.0 to 1.5.

In an embodiment of the disclosure, spheroidal MgCl₂ support particleshave a particle size distribution characterized by a Dm/Dn of ≤3.0,where Dm is the mass average diameter of the catalyst particles and Dnis the number average diameter of the catalyst particles.

In an embodiment of the disclosure, the spheroidal MgCl₂ supportparticles have a Dm/Dn of 2.5 or less. In an embodiment of thedisclosure, the spheroidal MgCl₂ support particles have a Dm/Dn of 2.0or less. In an embodiment of the disclosure, the spheroidal MgCl₂support particles have a Dm/Dn or 1.5 or less. In further embodiments ofthe disclosure, the spheroidal MgCl₂ support particles have a Dm/Dn offrom 1.0 to 3.0, or from 1.0 to 2.75, or from 1.0 to 2.5, or from 1.0 to2.0, or from 1.0 to 1.5.

The magnesium chloride support used in the present disclosure, is aspheroidal magnesium chloride support which is substantially free ofelectron donor compounds. By “substantially free”, or “substantiallyremove” it is meant that the MgCl₂ support will contain less than about2.5 percent by weight of an electron donor compound. Indeed, thepresence of organic electron donor compounds may lead to deactivation ofthe phosphinimine catalyst or make it difficult to load thephosphinimine catalyst on to the MgCl₂ support. Hence, although requiredfor the formation of the spheroidal magnesium chloride support, asdescribed above, an electron donor is preferably, in the presentdisclosure, reduced to sufficiently low quantities prior to addition ofthe phosphinimine catalyst to the support (e.g. the amount of anelectron donor is reduced to an amount of less than about 2.5 percent byweight of the magnesium chloride support).

Any method which removes or reduces the amount of the electron donorcompound from/in the spheroidal magnesium chloride support withoutsignificantly altering the morphology of the same may be used in thepresent disclosure.

In an embodiment of the disclosure, the organic donor compound can beremoved without significantly altering the morphology of the spheroidalmagnesium chloride support by treating the support with heat, optionalunder vacuum pressure. By vacuum pressure, it is meant the pressure isreduced to below atmospheric pressure.

In embodiments of the disclosure, the spheroidal MgCl₂ support willcomprise less than 2.5 weight percent, or less than 2.0 weight percent,or less than 1.5 weight percent, or less than 1.0 weight percent of anelectron donor compound.

In an embodiment of the disclosure, the spheroidal MgCl₂ support willcomprise less than 2.5 weight percent of an electron donor compoundafter subjecting the spheroidal MgCl₂ support to heat treatment.

In an embodiment of the disclosure, the spheroidal MgCl₂ support willcomprise less than 2.0 weight percent of an electron donor compoundafter subjecting the spheroidal MgCl₂ support to heat treatment.

In an embodiment of the disclosure, the spheroidal MgCl₂ support willcomprise less than 1.5 weight percent of an electron donor compoundafter subjecting the spheroidal MgCl₂ support to heat treatment.

In an embodiment of the disclosure, the spheroidal MgCl₂ support willcomprise less than 1.0 weight percent of an electron donor compoundafter subjecting the spheroidal MgCl₂ support to heat treatment.

In an embodiment of the disclosure, the organic donor compound can beremoved without significantly altering the morphology of the spheroidalmagnesium chloride support by treating the support with anorganoaluminum compound (e.g. an aluminum compound having alkyl or arylor alkylaryl group(s) attached to aluminum), an or an organoaluminumhalide compound (e.g. an aluminum compound having both alkyl or aryl orakylaryl group(s) and halide(s) attached to aluminum), or anorganohydrocarbyloxyaluminum compound (e.g. an aluminum compound havingboth alkyl, or aryl or alkylaryl group(s) and alkoxy or aryloxy oralkylaryloxy group(s) attached to aluminum). Suitable non-limitingexamples of organoaluminum compounds include triisobutylaluminum,triethylaluminum, trimethylaluminum or other trialkylaluminum compounds.Suitable non-limiting examples of organoaluminum halide compoundsinclude diethylaluminum chloride or other dialkyl aluminum chloridecompounds.

In an embodiment of the disclosure, the spheroidal MgCl₂ support willcomprise less than 2.5 weight percent of an electron donor compoundafter treating the spheroidal MgCl₂ support with an organoaluminumcompound, or an organoaluminum chloride compound or anorganohydrocarbyloxyaluminum compound.

In an embodiment of the disclosure, the spheroidal MgCl₂ support willcomprise less than 2.0 weight percent of an electron donor compoundafter treating the spheroidal MgCl₂ support with an organoaluminumcompound, or an organoaluminum chloride compound or anorganohydrocarbyloxyaluminum compound.

In an embodiment of the disclosure, the spheroidal MgCl₂ support willcomprise less than 1.5 weight percent of an electron donor compoundafter treating the spheroidal MgCl₂ support with an organoaluminumcompound, or an organoaluminum chloride compound or anorganohydrocarbyloxyaluminum compound.

In an embodiment of the disclosure a spheroidal olefin polymerizationcatalyst has a particle size distribution characterized by a Dm*/Dn ofless than 3.0, where the catalyst comprises a phosphinimine catalyst, acocatalyst, and a spheroidal magnesium chloride support, where themagnesium chloride support comprises particles with a mass averagediameter Dm of 5 to 100 μm, a particle size distribution characterizedby a Dm/Dn of less than 3.0, and comprises less than 2% by weight of anelectron donor compound.

In an embodiment of the disclosure a spheroidal olefin polymerizationcatalyst has a particle size distribution characterized by a Dm*/Dn ofless than 3.0, where the catalyst comprises a phosphinimine catalyst, acocatalyst, and a spheroidal magnesium chloride support, where themagnesium chloride support comprises particles with a mass averagediameter Dm of 5 to 100 μm, a particle size distribution characterizedby a Dm/Dn of less than 3.0, and comprises less than 2% by weight of anorganic electron donor compound.

In an embodiment of the disclosure a spheroidal olefin polymerizationcatalyst has a particle size distribution characterized by a Dm*/Dn ofless than 3.0, where the catalyst comprises a phosphinimine catalyst, acocatalyst, and a spheroidal magnesium chloride support, where themagnesium chloride support comprises particles with a mass averagediameter Dm of 5 to 100 μm, a particle size distribution characterizedby a Dm/Dn of less than 3.0, and comprises less than 2% by weight of anon-protic ether.

In an embodiment of the disclosure, a spheroidal olefin polymerizationcatalyst having a particle size distribution characterized by a Dm*/Dnof less than 3.0 is made by carrying out the following steps:

-   -   i) combining a dialkylmagnesium compound with a non-protic        ether,    -   ii) combining the product of step i) with a source of chloride        anion,    -   iii) treating the product of step ii) to remove the non-protic        ether,    -   iv) combining the product of step iii) with a phosphinimine        catalyst and a cocatalyst.

In an embodiment of the disclosure, a spheroidal olefin polymerizationcatalyst having a particle size distribution characterized by a Dm*/Dnof less than 3.0 is made by carrying out the following steps:

-   -   i) combining a dialkylmagnesium compound with a non-protic        ether,    -   ii) combining the product of step i) with a source of chloride        anion,    -   iii) heating the product of step ii) to remove the non-protic        ether,    -   iv) combining the product of step iii) with a phosphinimine        catalyst and a cocatalyst.

In an embodiment of the disclosure, a spheroidal olefin polymerizationcatalyst having a particle size distribution characterized by a Dm*/Dnof less than 3.0 is made by carrying out the following steps:

-   -   i) combining a dialkylmagnesium compound with a non-protic        ether,    -   ii) combining the product of step i) with a source of chloride        anion,    -   iii) treating the product of step ii) with an        alkylaluminumchloride compound to remove the non-protic ether,    -   iv) combining the product of step iii) with a phosphinimine        catalyst and a cocatalyst.

The present disclosure is not limited to any particular procedure forsupporting a phosphinimine catalyst or cocatalyst components on themagnesium chloride support. Processes for depositing such catalysts(e.g. a phosphinimine catalyst) as well as a cocatalyst (e.g. MMO) on asupport are well known in the art (for some non-limiting examples ofcatalyst supporting methods, see “Supported Catalysts” by James H. Clarkand Duncan J. Macquarrie, published online Nov. 15, 2002 in theKirk-Othmer Encyclopedia of Chemical Technology Copyright© 2001 by JohnWiley & Sons, Inc.; for some non-limiting methods to support anorganotransition metal catalyst see U.S. Pat. No. 5,965,677). Forexample, a phosphinimine catalyst may be added to a support byco-precipitation with the support material. The cocatalyst can be addedto the support before and/or after the phosphinimine catalyst ortogether with the phosphinimine catalyst. Optionally, the cocatalyst canbe added to a supported phosphinimine catalyst in situ or aphosphinimine catalyst may be added to the support in situ or aphosphinimine catalyst can be added to a supported activator in situ. Aphosphinimine catalyst and/or a cocatalyst may be slurried or dissolvedin a suitable diluent or solvent and then added to the support. Suitablesolvents or diluents include but are not limited to hydrocarbons andmineral oil. A phosphinimine catalyst for example, may be added to thesolid support, in the form of a solid, solution or slurry, followed bythe addition of the cocatalyst in solid form or as a solution or slurry.Phosphinimine catalyst, cocatalyst, and support can be mixed together inthe presence or absence of a solvent.

In an embodiment of the disclosure, the phosphinimine catalyst andcocatalyst are combined in an inert solvent or diluent and thecombination is added to a MgCl₂ support.

Some non-limiting examples of phosphinimine catalysts can be found inU.S. Pat. Nos. 6,342,463; 6,235,672; 6,372,864; 6,984,695; 6,063,879;6,777,509 and 6,277,931 all of which are incorporated by referenceherein.

Preferably, the phosphinimine catalyst is based on metals from group 4,which includes titanium, hafnium and zirconium. The most preferredphosphinimine catalysts are group 4 metal complexes in their highestoxidation state.

The phosphinimine catalysts described herein, usually require activationby one or more cocatalytic or activator species in order to providepolymer from olefins.

A phosphinimine catalyst is a compound (typically an organometalliccompound) based on a group 3, 4 or 5 metal and which is characterized ashaving at least one phosphinimine ligand. Any compounds/complexes havinga phosphinimine ligand and which display catalytic activity for ethylene(co)polymerization may be called “phosphinimine catalysts.”

In an embodiment of the disclosure, a phosphinimine catalyst is definedby the formula: (L)_(n)(PI)_(m)MX_(p) where M is a transition metalselected from Ti, Hf, Zr; PI is a phosphinimine ligand; L is acyclopentadienyl-type ligand; X is an activatable ligand; m is 1 or 2; nis 0 or 1; and p is determined by the valency of the metal M. Preferablym is 1, n is 1 and p is 2.

In an embodiment of the disclosure, a phosphinimine catalyst is definedby the formula: (L)(PI)MX₂ where M is a transition metal selected fromTi, Hf, Zr; PI is a phosphinimine ligand; L is a cyclopentadienyl-typeligand; and X is an activatable ligand.

The phosphinimine ligand is defined by the formula: R₃P═N—, where Nbonds to the metal, and wherein each R is independently selected fromthe group consisting of a hydrogen atom; a halogen atom; C₁₋₂₀hydrocarbyl radicals which are unsubstituted or further substituted byone or more halogen atom and/or C₁₋₂₀ alkyl radical; C₁₋₈ alkoxyradical; C₆₋₁₀ aryl or aryloxy radical (the aryl or aryloxy radicaloptionally being unsubstituted or further substituted by one or morehalogen atom and/or C₁₋₂₀ alkyl radical); amido radical; silyl radicalof the formula: —SiR′₃ wherein each R′ is independently selected fromthe group consisting of hydrogen, a C₁₋₈ alkyl or alkoxy radical, C₆₋₁₀aryl or aryloxy radicals; and germanyl radical of the formula: —GeR′₃wherein R′ is as defined above.

In an embodiment of the disclosure the phosphinimine ligand is chosen sothat each R is a hydrocarbyl radical. In a particular embodiment of thedisclosure, the phosphinimine ligand is tri-(tertiarybutyl)phosphinimine(i.e. where each R is a tertiary butyl group, or “t-Bu” for short).

In an embodiment of the disclosure, the phosphinimine catalyst is agroup 4 compound/complex which contains one phosphinimine ligand (asdescribed above) and one ligand L which is either acyclopentadienyl-type ligand or a heteroatom ligand.

As used herein, the term “cyclopentadienyl-type” ligand is meant toinclude ligands which contain at least one five-carbon ring which isbonded to the metal via eta-5 (or in some cases eta-3) bonding. Thus,the term “cyclopentadienyl-type” includes, for example, unsubstitutedcyclopentadienyl, singly or multiply substituted cyclopentadienyl,unsubstituted indenyl, singly or multiply substituted indenyl,unsubstituted fluorenyl and singly or multiply substituted fluorenyl.Hydrogenated versions of indenyl and fluorenyl ligands are alsocontemplated for use in the current disclosure, so long as thefive-carbon ring which bonds to the metal via eta-5 (or in some caseseta-3) bonding remains intact. Substituents for a cyclopentadienylligand, an indenyl ligand (or hydrogenated version thereof) and afluorenyl ligand (or hydrogenated version thereof) may be selected fromthe group consisting of a C₁₋₃₀ hydrocarbyl radical (which hydrocarbylradical may be unsubstituted or further substituted by for example ahalide and/or a hydrocarbyl group; for example a suitable substitutedC₁₋₃₀ hydrocarbyl radical is a pentafluorobenzyl group such as—CH₂C₆F₅);a halogen atom; a C₁₋₈ alkoxy radical; a C₆₋₁₀ aryl or aryloxy radical(each of which may be further substituted by for example a halide and/ora hydrocarbyl group; for example a suitable C₆₋₁₀ aryl group is aperfluoroaryl group such as—C₆F₅); an amido radical which isunsubstituted or substituted by up to two C₁₋₈ alkyl radicals; aphosphido radical which is unsubstituted or substituted by up to twoC₁₋₈ alkyl radicals; a silyl radical of the formula —Si(R′)₃ whereineach R′ is independently selected from the group consisting of hydrogen,a C₁₋₈ alkyl or alkoxy radical, C₆₋₁₀ aryl or aryloxy radicals; and agermanyl radical of the formula —Ge(R′)₃ wherein R′ is as defineddirectly above.

As used herein, the term “heteroatom ligand” refers to a ligand whichcontains at least one heteroatom selected from the group consisting ofboron, nitrogen, oxygen, silicon, phosphorus or sulfur. The heteroatomligand may be sigma or pi-bonded to the metal. Exemplary heteroatomligands include but are not limited to “silicon containing” ligands,“amido” ligands, “alkoxy” ligands, “boron heterocycle” ligands and“phosphole” ligands.

Silicon containing ligands are defined by the formula:-(μ)SiR^(x)R^(y)R^(z) where the “-” denotes a bond to the transitionmetal and μ is sulfur or oxygen. The substituents on the Si atom, namelyR^(x), R^(y) and R^(z) are required in order to satisfy the bondingorbital of the Si atom. The use of any particular substituent R^(x),R^(y) or R^(z) is not especially important. In an embodiment of thedisclosure, each of R^(x), R^(y) and R^(z) is a C₁₋₂ hydrocarbyl group(i.e. methyl or ethyl) simply because such materials are readilysynthesized from commercially available materials.

The term “amido” is meant to convey its broad, conventional meaning.Thus, these ligands are characterized by (a) a metal-nitrogen bond and(b) the presence of two substituents (which are typically simple alkylor silyl groups) on the nitrogen atom. The term “alkoxy” is alsointended to convey its conventional meaning. Thus, these ligands arecharacterized by (a) a metal oxygen bond, and (b) the presence of ahydrocarbyl group bonded to the oxygen atom. The hydrocarbyl group maybe a ring structure and may optionally be substituted (e.g. 2,6di-tertiary butyl phenoxy).

The “boron heterocyclic” ligands are characterized by the presence of aboron atom in a closed ring ligand. This definition includesheterocyclic ligands which also contain a nitrogen atom in the ring.These ligands are well known to those skilled in the art of olefinpolymerization and are fully described in the literature (see, forexample, U.S. Pat. Nos. 5,637,659 and 5,554,775 and the references citedtherein).

The term “phosphole” is also meant to convey its conventional meaning.“Phospholes” are cyclic dienyl structures having four carbon atoms andone phosphorus atom in the closed ring. The simplest phosphole is C₄PH₄(which is analogous to cyclopentadiene with one carbon in the ring beingreplaced by phosphorus). The phosphole ligands may be substituted with,for example, C₁₋₂₀ hydrocarbyl radicals (which may, optionally, containhalogen substituents); phosphido radicals; amido radicals; silyl oralkoxy radicals. Phosphole ligands are also well known to those skilledin the art of olefin polymerization and are described as such in U.S.Pat. No. 5,434,116.

The term “activatable ligand” refers to a ligand which may be activatedby a cocatalyst (also referred to as an “activator”), to facilitateolefin polymerization. An activatable ligand X may be cleaved from themetal center M via a protonolysis reaction or abstracted from the metalcenter M by suitable acidic or electrophilic catalyst activatorcompounds (also known as “co-catalyst” compounds) respectively, examplesof which are described below. The activatable ligand X may also betransformed into another ligand which is cleaved or abstracted from themetal center M (e.g. a halide may be converted to an alkyl group).Without wishing to be bound by any single theory, protonolysis orabstraction reactions generate an active “cationic” metal center whichcan polymerize olefins. In embodiments of the present disclosure, theactivatable ligand, X is independently selected from the groupconsisting of a hydrogen atom; a halogen atom; a C₁₋₁₀ hydrocarbylradical; a alkoxy radical; a C₆₋₁₀ aryl oxide radical, each of whichsaid hydrocarbyl, alkoxy, and aryl oxide radicals may be unsubstitutedby or further substituted by a halogen atom, a C₁₋₈ alkyl radical, aC₁₋₈ alkoxy radical, a C₆₋₁₀ aryl or aryloxy radical; an amido radicalwhich is unsubstituted or substituted by up to two C₁₋₈ alkyl radicals;and a phosphido radical which is unsubstituted or substituted by up totwo C₁₋₈ alkyl radicals. Two activatable X ligands may also be joined toone another and form for example, a substituted or unsubstituted dieneligand (i.e. 1,3-diene); or a delocalized heteroatom containing groupsuch as an acetate group.

The number of activatable ligands depends upon the valency of the metaland the valency of the activatable ligand. The preferred phosphiniminecatalysts are based on group 4 metals in their highest oxidation state(i.e. 4⁺). Particularly suitable activatable ligands are monoanionicsuch as a halide (e.g. chloride) or a hydrocarbyl (e.g. methyl, benzyl).

In some instances, the metal of the phosphinimine catalyst may not be inthe highest oxidation state. For example, a titanium (III) componentwould contain only one activatable ligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula, (L)(PI)MX₂, where M is Ti, Zr or Hf; PI is a phosphinimineligand having the formula R₃P═N—, where R is independently selected fromthe group consisting of hydrogen, halogen, and C₁-C₂₀ hydrocarbyl; L isa ligand selected from the group consisting of cyclopentadienyl,substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl,and substituted fluorenyl; and X is an activatable ligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (L)((t-Bu)₃P═N)TiX₂, where L is a ligand selected from thegroup consisting of cyclopentadienyl, substituted cyclopentadienyl,indenyl, and substituted indenyl; and X is an activatable ligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (L)((t-Bu)₃P═N)TiX₂, where L is a ligand selected from thegroup consisting of a substituted cyclopentadienyl and substitutedindenyl; and X is an activatable ligand.

In an embodiment of the disclosure, the phosphinimine catalyst containsa phosphinimine ligand, a cyclopentadienyl ligand (“Cp” for short) andtwo chloride or two methyl ligands bonded to the group 4 metal.

In an embodiment of the disclosure, the phosphinimine catalyst containsa phosphinimine ligand, a singly or multiply substitutedcyclopentadienyl ligand and two chloride or two methyl ligands bonded tothe group 4 metal.

In an embodiment of the disclosure, the phosphinimine catalyst containsa phosphinimine ligand, a perfluoroaryl substituted cyclopentadienylligand and two chloride or two methyl ligands bonded to the group 4metal.

In an embodiment of the disclosure, the phosphinimine catalyst containsa phosphinimine ligand, a perfluorophenyl substituted cyclopentadienylligand (i.e. Cp-C₆F₅) and two chloride or two methyl ligands bonded tothe group 4 metal.

In an embodiment of the disclosure, the phosphinimine catalyst containsa 1,2-substituted cyclopentadienyl ligand and a phosphinimine ligandwhich is substituted by three tertiary butyl substituents.

In an embodiment of the disclosure, the phosphinimine catalyst containsa 1,2 substituted cyclopentadienyl ligand (e.g. a 1,2-(R*)(Ar—F)Cp)where the substituents are selected from R* a hydrocarbyl group, andAr—F a perfluorinated aryl group, a 2,6 (i.e. ortho) fluoro substitutedphenyl group, a 2,4,6 (i.e. ortho/para) fluoro substituted phenyl group,or a 2,3,5,6 (i.e. ortho/meta) fluoro substituted phenyl grouprespectively.

In the present disclosure, 1,2 substituted cyclopentadienyl ligands suchas for example 1,2-(R*)(Ar—F)Cp ligands may contain as impurities 1,3substituted analogues such as for example 1,3-(R*)(Ar—F)Cp ligands.Hence, phosphinimine catalysts having a 1,2 substituted Cp ligand maycontain as an impurity, a phosphinimine catalyst having a 1,3substituted Cp ligand. Alternatively, the current disclosurecontemplates the use of 1,3 substituted Cp ligands as well as the use ofmixtures of varying amounts of 1,2 and 1,3 substituted Cp ligands togive phosphinimine catalysts having 1,3 substituted Cp ligands or mixedphosphinimine catalysts having 1,2 and 1,3 substituted Cp ligands.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1,2-(R*)(Ar—F)Cp)M(N═P(t-Bu)₃)X₂ where R* is a hydrocarbylgroup; Ar—F is a perfluorinated aryl group, a 2,6 (i.e. ortho) fluorosubstituted phenyl group, a 2,4,6 (i.e. ortho/para) fluoro substitutedphenyl group, or a 2,3,5,6 (i.e. ortho/meta) fluoro substituted phenylgroup; M is Ti, Zr or Hf; and X is an activatable ligand. In anembodiment of the disclosure, the phosphinimine catalyst has theformula: (1,2-(R*)(Ar—F)Cp)M(N═P(t-Bu)₃)X₂ where R* is an alkyl group;Ar—F is a perfluorinated aryl group, a 2,6 (i.e. ortho) fluorosubstituted phenyl group, a 2,4,6 (i.e. ortho/para) fluoro substitutedphenyl group or a 2,3,5,6 (i.e. ortho/meta) fluoro substituted phenylgroup; M is Ti, Zr or Hf; and X is an activatable ligand. In anembodiment of the disclosure, the phosphinimine catalyst has theformula: (1,2-(R*)(Ar—F)Cp)M(N═P(t-Bu)₃)X₂ where R* is a hydrocarbylgroup having from 1 to 20 carbons; Ar—F is a perfluorinated aryl group;M is Ti, Zr or Hf; and X is an activatable ligand. In an embodiment ofthe disclosure, the phosphinimine catalyst has the formula:(1,2-(R*)(Ar—F)Cp)M(N═P(t-Bu)₃)X₂ where R* is a straight chain alkylgroup; Ar—F is a perfluorinated aryl group, a 2,6 (i.e. ortho) fluorosubstituted phenyl group, a 2,4,6 (i.e. ortho/para) fluoro substitutedphenyl group, or a 2,3,5,6 (i.e. ortho/meta) fluoro substituted phenylgroup; M is Ti, Zr or Hf; and X is an activatable ligand. In anembodiment of the disclosure, the phosphinimine catalyst has theformula: (1,2-(n-R*)(Ar—F)Cp)Ti(N═P(t-Bu)₃)X₂ where R* is a straightchain alkyl group; Ar—F is a perfluorinated aryl group; M is Ti, Zr orHf; and X is an activatable ligand. In an embodiment of the disclosure,the phosphinimine catalyst has the formula:(1,2-(R*)(C₆F₅)Cp)M(N═P(t-Bu)₃)X₂ where R* is a hydrocarbyl group having1 to 20 carbon atoms; M is Ti, Zr or Hf; and X is an activatable ligand.In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1,2-(n-R*)(C₆F₅)Cp)M(N═P(t-Bu)₃)X₂ where R* is a straightchain alkyl group; M is Ti, Zr or Hf; and X is an activatable ligand. Infurther embodiments, M is Ti and R* is any one of a methyl, ethyl,n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl group. Infurther embodiments, X is chloride or methide.

The term “perfluorinated aryl group” means that each hydrogen atomattached to a carbon atom in an aryl group has been replaced with afluorine atom as is well understood in the art (e.g. a perfluorinatedphenyl group or substituent has the formula —C₆F₅). In embodiments ofthe disclosure, Ar—F is selected from the group comprisingperfluorinated phenyl or perfluorinated naphthyl groups.

Some phosphinimine catalysts which may be used in the present disclosureinclude: ((C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂;(1,2-(n-propyl)(C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂,(1,2-(n-butyl)(C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂ and(1,2-(n-hexyl)(C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂.

In an embodiment of the disclosure, the phosphinimine catalyst will havea single or multiply substituted indenyl ligand and a phosphinimineligand which is substituted by three tertiary butyl substituents.

An indenyl ligand (or “Ind” for short) as defined in the presentdisclosure will have framework carbon atoms with the numbering schemeprovided below, so the location of a substituent can be readilyidentified.

In an embodiment of the disclosure, the phosphinimine catalyst will havea singly substituted indenyl ligand and a phosphinimine ligand which issubstituted by three tertiary butyl substituents.

In an embodiment of the disclosure, the phosphinimine catalyst will havea singly or multiply substituted indenyl ligand where the substituent isselected from the group consisting of a substituted or unsubstitutedalkyl group, a substituted or an unsubstituted aryl group, and asubstituted or unsubstituted benzyl (e.g. C₆H₅CH₂—) group. Suitablesubstituents for the alkyl, aryl or benzyl group may be selected fromthe group consisting of alkyl groups, aryl groups, alkoxy groups,aryloxy groups, alkylaryl groups (e.g. a benzyl group), arylalkyl groupsand halide groups. In an embodiment of the disclosure, the phosphiniminecatalyst will have a singly substituted indenyl ligand, R^(¥)-Indenyl,where the R^(¥) substituent is a substituted or unsubstituted alkylgroup, a substituted or an unsubstituted aryl group, or a substituted orunsubstituted benzyl group. Suitable substituents for an R^(¥) alkyl,R^(¥) aryl or R^(¥) benzyl group may be selected from the groupconsisting of alkyl groups, aryl groups, alkoxy groups, aryloxy groups,alkylaryl groups (e.g. a benzyl group), arylalkyl groups and halidegroups.

In an embodiment of the disclosure, the phosphinimine catalyst will havean indenyl ligand having at least a 1-position substituent (1-R^(¥))where the substituent R^(¥) is a substituted or unsubstituted alkylgroup, a substituted or an unsubstituted aryl group, or a substituted orunsubstituted benzyl group. Suitable substituents for an R^(¥) alkyl,R^(¥) aryl or R^(¥) benzyl group may be selected from the groupconsisting of alkyl groups, aryl groups, alkoxy groups, aryloxy groups,alkylaryl groups (e.g. a benzyl group), arylalkyl groups and halidegroups.

In an embodiment of the disclosure, the phosphinimine catalyst will havea singly substituted indenyl ligand, 1-R^(¥)-Indenyl where thesubstituent R_(¥) is in the 1-position of the indenyl ligand and is asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedaryl group, or a substituted or an unsubstituted benzyl group. Suitablesubstituents for an R^(¥) alkyl, R^(¥) aryl or R^(¥) benzyl group may beselected from the group consisting of alkyl groups, aryl groups, alkoxygroups, aryloxy groups, alkylaryl groups (e.g. a benzyl group),arylalkyl groups and halide groups.

In an embodiment of the disclosure, the phosphinimine catalyst will havea singly substituted indenyl ligand, 1-R^(¥)-Indenyl, where thesubstituent R^(¥) is a (partially/fully) halide substituted alkyl group,a (partially/fully) halide substituted benzyl group, or a(partially/fully) halide substituted aryl group.

In an embodiment of the disclosure, the phosphinimine catalyst will havea singly substituted indenyl ligand, 1-R^(¥)-Indenyl, where thesubstituent R^(¥) is a (partially/fully) halide substituted benzylgroup.

When present on an indenyl ligand, a benzyl group can be partially orfully substituted by halide atoms, preferably fluoride atoms. The arylgroup of the benzyl group may be a perfluorinated aryl group, a 2,6(i.e. ortho) fluoro substituted phenyl group, 2,4,6 (i.e. ortho/para)fluoro substituted phenyl group or a 2,3,5,6 (i.e. ortho/meta) fluorosubstituted phenyl group respectively. The benzyl group is, in anembodiment of the disclosure, located at the 1 position of the indenylligand.

In an embodiment of the disclosure, the phosphinimine catalyst will havea singly substituted indenyl ligand, 1-R^(¥)-Indenyl, where thesubstituent R^(¥) is a pentafluorobenzyl (C₆F₅CH₂—) group.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1-R^(¥)-(Ind))M(N═P(t-Bu)₃)X₂ where R^(¥) is a substituted orunsubstituted alkyl group, a substituted or an unsubstituted aryl group,or a substituted or unsubstituted benzyl group, wherein substituents forthe alkyl, aryl or benzyl group are selected from the group consistingof alkyl, aryl, alkoxy, aryloxy, alkylaryl, arylalkyl and halidesubstituents; M is Ti, Zr or Hf; and X is an activatable ligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1-R^(¥)-(Ind))M(N═P(t-Bu)₃)X₂ where R^(¥) is an alkyl group,an aryl group or a benzyl group and wherein each of the alkyl group, thearyl group, and the benzyl group may be unsubstituted or substituted byat least one fluoride atom; M is Ti, Zr or Hf; and X is an activatableligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1-R^(¥)-(Ind))M(N═P(t-Bu)₃)X₂ where R^(¥) is an alkyl group,an aryl group or a benzyl group and wherein each of the alkyl group, thearyl group, and the benzyl group may be unsubstituted or substituted byat least one halide atom; M is Ti, Zr or Hf; and X is an activatableligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1-R^(¥)-(Ind))Ti(N═P(t-Bu)₃)X₂ where R^(¥) is an alkyl group,an aryl group or a benzyl group and wherein each of the alkyl group, thearyl group, and the benzyl group may be unsubstituted or substituted byat least one fluoride atom; and X is an activatable ligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1-C₆F₅CH₂-Ind)M(N═P(t-Bu)₃)X₂, where M is Ti, Zr or Hf; and Xis an activatable ligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1-C₆F₅CH₂-Ind)Ti(N═P(t-Bu)₃)X₂, where X is an activatableligand.

In an embodiment of the disclosure, the phosphinimine catalyst has theformula: (1-C₆F₅CH₂-Ind)Ti(N═P(t-Bu)₃)Cl₂.

In the present disclosure, the phosphinimine catalyst is used incombination with at least one activator (or “cocatalyst”) to form anactive polymerization catalyst system for olefin polymerization.Activators (i.e. cocatalysts) include ionic activator cocatalysts andhydrocarbyl aluminoxane cocatalysts.

The activator used to activate the phosphinimine catalyst can be anysuitable activator including one or more activators selected from thegroup consisting of alkylaluminoxanes and ionic activators, optionallytogether with an alkylating agent.

The alkylaluminoxanes are complex aluminum compounds of the formula: R³₂Al¹O(R³Al¹O)_(m)Al¹R³ ₂, wherein each R³ is independently selected fromthe group consisting of C₁₋₂₀ hydrocarbyl radicals and m is from 3 to50. Optionally a hindered phenol can be added to the alkylaluminoxane toprovide a molar ratio of Al¹:hindered phenol of from 2:1 to 5:1 when thehindered phenol is present.

In an embodiment of the disclosure, R³ of the alkylaluminoxane, is amethyl radical and m is from 10 to 40.

The alkylaluminoxanes are typically used in substantial molar excesscompared to the amount of group 4 transition metal in the phosphiniminecatalyst. The Al¹:group 4 transition metal molar ratios are from 10:1 to10,000:1, in other cases from about 30:1 to 500:1.

In an embodiment of the disclosure, the catalyst activator ismethylaluminoxane (MAO).

In an embodiment of the disclosure, the catalyst activator is modifiedmethylaluminoxane (MMAO).

It is well known in the art, that the alkylaluminoxane can serve dualroles as both an alkylator and an activator. Hence, an alkylaluminoxaneactivator is often used in combination with activatable ligands such ashalogens.

Alternatively, the activator of the present disclosure may be acombination of an alkylating agent (which may also serve as a scavenger)with an activator capable of ionizing the group 4 metal of thephosphinimine catalyst (i.e. an ionic activator). In this context, theactivator can be chosen from one or more alkylaluminoxane and/or anionic activator.

When present, the alkylating agent may be selected from the groupconsisting of (R⁴)_(p)MgX² _(2-p) wherein X² is a halide and each R⁴ isindependently selected from the group consisting of C₁₋₁₀ alkyl radicalsand p is 1 or 2; R⁴Li wherein in R⁴ is as defined above, (R⁴)_(q)ZnX²_(2-q) wherein R⁴ is as defined above, X² is halogen and q is 1 or 2;(R⁴)_(s)Al²X² _(3-s) wherein R⁴ is as defined above, X² is halogen and sis an integer from 1 to 3. Preferably in the above compounds R⁴ is aC₁₋₄ alkyl radical, and X² is chlorine. Commercially available compoundsinclude triethyl aluminum (TEAL), diethyl aluminum chloride (DEAC),dibutyl magnesium ((Bu)₂Mg), and butyl ethyl magnesium (BuEtMg orBuMgEt).

The ionic activator may be selected from the group consisting of: (i)compounds of the formula [R⁵]⁺ [B(R⁶)₄]⁻ wherein B is a boron atom, R⁵is a cyclic C₅₋₇ aromatic cation or a triphenyl methyl cation and eachR⁶ is independently selected from the group consisting of phenylradicals which are unsubstituted or substituted with from 3 to 5substituents selected from the group consisting of a fluorine atom, aC₁₋₄ alkyl or alkoxy radical which is unsubstituted or substituted by afluorine atom; and a silyl radical of the formula —Si—(R⁷)₃; whereineach R⁷ is independently selected from the group consisting of ahydrogen atom and a C₁₋₄ alkyl radical; and (ii) compounds of theformula [(R⁸)_(t)ZH]⁺ [B(R⁶)₄]⁻ wherein B is a boron atom, H is ahydrogen atom, Z is a nitrogen atom or phosphorus atom, t is 2 or 3 andR⁸ is selected from the group consisting of C₁₋₈ alkyl radicals, aphenyl radical which is unsubstituted or substituted by up to three C₁₋₄alkyl radicals, or one R⁸ taken together with a nitrogen atom may forman anilinium radical and R⁶ is as defined above; and (iii) compounds ofthe formula B(R⁶)₃ wherein R⁶ is as defined above.

In the above compounds preferably R⁶ is a pentafluorophenyl radical, andR⁵ is a triphenylmethyl cation, Z is a nitrogen atom and R⁸ is a C₁₋₄alkyl radical or one R⁸ taken together with a nitrogen atom forms ananilinium radical (e.g. PhR⁸ ₂NH⁺, which is substituted by two R⁸radicals such as for example two C₁₋₄ alkyl radicals).

Examples of compounds capable of ionizing the phosphinimine catalystinclude the following compounds: triethylammonium tetra(phenyl)boron,tripropylammonium tetra(phenyl)boron, tri(n-butyl)ammoniumtetra(phenyl)boron, trimethylammonium tetra(p-tolyl)boron,trimethylammonium tetra(o-tolyl)boron, tributylammoniumtetra(pentafluorophenyl)boron, tripropylammonium tetra(o,p-dimethylphenyl)boron, tributylammoniumtetra(m,m-dimethylphenyl)boron, tributylammoniumtetra(p-trifluoromethylphenyl)boron, tributylammoniumtetra(pentafluorophenyl)boron, tri(n-butyl)ammonium tetra(o-tolyl)boron, N,N-diethylanilinium tetra(phenyl)boron,N,N-diethylanilinium tetra(phenyl)boron, N,N-diethylaniliniumtetra(phenyl)n-butylboron, N,N-2,4,6-pentamethylaniliniumtetra(phenyl)boron, di-(isopropyl)ammoniumtetra(pentafluorophenyl)boron, dicyclohexylammonium tetra (phenyl)boron,triphenylphosphonium tetra)phenyl)boron, tri(methylphenyl)phosphoniumtetra(phenyl)boron, tri(dimethylphenyl)phosphonium tetra(phenyl)boron,tropillium tetrakispentafluorophenyl borate, triphenylmethyliumtetrakispentafluorophenyl borate, benzene (diazonium)tetrakispentafluorophenyl borate, tropilliumphenyltris-pentafluorophenyl borate, triphenylmethyliumphenyl-trispentafluorophenyl borate, benzene (diazonium)phenyltrispentafluorophenyl borate, tropillium tetrakis(2,3,5,6-tetrafluorophenyl) borate, triphenylmethylium tetrakis(2,3,5,6-tetrafluorophenyl) borate, benzene (diazonium) tetrakis(3,4,5-trifluorophenyl) borate, tropillium tetrakis(3,4,5-trifluorophenyl) borate, benzene (diazonium) tetrakis(3,4,5-trifluorophenyl) borate, tropillium tetrakis(1,2,2-trifluoroethenyl) borate, trophenylmethylium tetrakis(1,2,2-trifluoroethenyl) borate, benzene (diazonium) tetrakis(1,2,2-trifluoroethenyl) borate, tropillium tetrakis(2,3,4,5-tetrafluorophenyl) borate, triphenylmethylium tetrakis(2,3,4,5-tetrafluorophenyl) borate, and benzene (diazonium) tetrakis(2,3,4,5-tetrafluorophenyl) borate.

Commercially available activators which are capable of ionizing thegroup 4 metal of the phosphinimine catalyst include:N,N-dimethylaniliniumtetrakispentafluorophenyl borate(“[Me₂NHPh][B(C₆F₅)₄]”); triphenylmethylium tetrakispentafluorophenylborate (“[Ph₃C][B(C₆F₅)₄]”); and trispentafluorophenyl boron and MAO(methylaluminoxane) and MMAO (modified methylaluminoxane).

The ionic activators compounds may be used in amounts which provide amolar ratio of group 4 transition metal to boron that will be from 1:1to 1:6.

Optionally, mixtures of alkylaluminoxanes and ionic activators can beused as activators in the polymerization catalyst.

Olefin polymerization processes which are compatible with the currentdisclosure include gas phase, slurry phase, and solution phasepolymerization processes.

In an embodiment of the disclosure, ethylene copolymerization with analpha-olefin is carried out in the gas phase, in for example a fluidizedbed reactor.

In an embodiment of the disclosure, ethylene copolymerization with analpha-olefin is carried out in the slurry phase, in for example a slurryphase loop or continuously stirred reactor.

Detailed descriptions of slurry polymerization processes are widelyreported in the patent literature. For example, particle formpolymerization, or a slurry process where the temperature is kept belowthe temperature at which the polymer goes into solution is described inU.S. Pat. No. 3,248,179. Slurry processes include those employing a loopreactor and those utilizing a single stirred reactor or a plurality ofstirred reactors in series, parallel, or combinations thereof.Non-limiting examples of slurry processes include continuous loop orstirred tank processes. Further examples of slurry processes aredescribed in U.S. Pat. No. 4,613,484.

Slurry processes are conducted in the presence of a hydrocarbon diluentsuch as an alkane (including isoalkanes), an aromatic or a cycloalkane.The diluent may also be the alpha olefin comonomer used incopolymerizations. Alkane diluents include propane, butanes, (i.e.normal butane and/or isobutane), pentanes, hexanes, heptanes andoctanes. The monomers may be soluble in (or miscible with) the diluent,but the polymer is not (under polymerization conditions). Thepolymerization temperature is in some cases from about 5° C. to about200° C., in other cases less than about 120° C., e.g. from about 10° C.to 100° C. The reaction temperature is selected so that an ethylenecopolymer is produced in the form of solid particles.

The reaction pressure is influenced by the choice of diluent andreaction temperature. For example, pressures may range from 15 to 45atmospheres (about 220 to 660 psi or about 1500 to about 4600 kPa) whenisobutane is used as diluent (see, for example, U.S. Pat. No. 4,325,849)to approximately twice that (i.e. from 30 to 90 atmospheres—about 440 to1300 psi or about 3000-9100 kPa) when propane is used (see U.S. Pat. No.5,684,097). The pressure in a slurry process is sufficiently high tokeep at least part of the ethylene monomer in the liquid phase. Thereaction typically takes place in a jacketed closed loop reactor havingan internal stirrer (e.g. an impeller) and at least one settling leg.Catalyst, monomers and diluents are fed to the reactor as liquids orsuspensions. The slurry circulates through the reactor and the jacket isused to control the temperature of the reactor. Through a series oflet-down valves, the slurry enters a settling leg and then is let downin pressure to flash the diluent and unreacted monomers and recover thepolymer generally in a cyclone. The diluent and unreacted monomers arerecovered and recycled back to the reactor.

A gas phase process is commonly carried out in a fluidized bed reactor.Such gas phase processes are widely described in the literature (see forexample U.S. Pat. Nos. 4,543,399; 4,588,790; 5,028,670; 5,317,036;5,352,749; 5,405,922; 5,436,304; 5,453,471; 5,462,999; 5,616,661 and5,668,228). In general, a fluidized bed gas phase polymerization reactoremploys a “bed” of polymer and catalyst which is fluidized by a flow ofmonomer and other optional components which are at least partiallygaseous. Heat is generated by the enthalpy of polymerization of themonomer (and optional comonomer(s)) flowing through the bed. Un-reactedmonomer and other optional gaseous components exit the fluidized bed andare contacted with a cooling system to remove this heat. The cooled gasstream, including monomer, and optional other components (such ascondensable liquids), is then re-circulated through the polymerizationzone, together with “make-up” monomer to replace that which waspolymerized on the previous pass. Simultaneously, polymer product iswithdrawn from the reactor. As will be appreciated by those skilled inthe art, the “fluidized” nature of the polymerization bed helps toevenly distribute/mix the heat of reaction and thereby minimize theformation of localized temperature gradients.

The reactor pressure in a gas phase process may vary from aboutatmospheric to about 600 Psig. In another embodiment, the pressure canrange from about 100 psig (690 kPa) to about 500 psig (3448 kPa). In yetanother embodiment, the pressure can range from about 200 psig (1379kPa) to about 400 psig (2759 kPa). In still another embodiment, thepressure can range from about 250 psig (1724 kPa) to about 350 psig(2414 kPa).

The reactor temperature in a gas phase process may vary according to theheat of polymerization as described above. In a one embodiment, thereactor temperature can be from about 30° C. to about 130° C. In anotherembodiment, the reactor temperature can be from about 60° C. to about120° C. In yet another embodiment, the reactor temperature can be fromabout 70° C. to about 110° C. In still yet another embodiment, thetemperature of a gas phase process can be from about 70° C. to about100° C.

The fluidized bed process described above is well adapted for thepreparation of polyethylene and polyethylene copolymers. Hence, monomersand comonomers include ethylene and C₃₋₁₂ alpha olefins which areunsubstituted or substituted by up to two C₁₋₆ hydrocarbyl radicals;C₈₋₁₂ vinyl aromatic olefins which are unsubstituted or substituted byup to two substituents selected from the group consisting of C₁₋₄hydrocarbyl radicals; and C₄₋₁₂ straight chained or cyclic diolefinswhich are unsubstituted or substituted by a C₁₋₄ hydrocarbyl radical.Illustrative non-limiting examples of alpha-olefins that may becopolymerized with ethylene include one or more of propylene, 1-butene,1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, and 1-decene,styrene, alpha methyl styrene, p-t-butyl styrene, and theconstrained-ring cyclic olefins such as cyclobutene, cyclopentene,dicyclopentadiene norbornene, hydrocarbyl-substituted norbornenes,alkenyl-substituted norbornenes and the like (e.g.5-methylene-2-norbornene and 5-ethylidene-2-norbornene,bicyclo-(2,2,1)-hepta-2,5-diene).

In an embodiment, the disclosure is directed toward a polymerizationprocess involving the polymerization of one or more of the monomer(s)and comonomer(s) including ethylene alone or in combination with one ormore linear or branched comonomer(s) having in some cases from 3 to 30carbon atoms, in other cases from 3-12 carbon atoms and in still othercases 4 to 8 carbon atoms. The process is particularly well suited tocopolymerization reactions involving polymerization of ethylene incombination with one or more of the comonomers, for example, thealpha-olefins: propylene, 1-butene, 1-pentene, 4-methyl-1-pentene,1-hexene, 1-octene, 1-decene, styrene and cyclic and polycyclic olefinssuch as cyclopentene, norbornene and cyclohexene or a combinationthereof. Other comonomers for use with ethylene can include polar vinylmonomers, diolefins such as 1,3-butadiene, 1,4-pentadiene,1,4-hexadiene, 1,5-hexadiene, norbornadiene, and other unsaturatedmonomers including acetylene and aldehyde monomers. Higher alpha-olefinsand polyenes or macromers can be used also. In some cases the comonomeris an alpha-olefin having from 3 to 15 carbon atoms, in other cases from4 to 12 carbon atoms and in still other cases 4 to 10 carbon atoms.

In an embodiment of the present disclosure, ethylene is copolymerizedwith an alpha olefin having from 3-10 carbon atoms and ethylene makes upat least 75 wt % of the total olefin feed entering the reactor.

In an embodiment of the present disclosure, ethylene is copolymerizedwith an alpha olefin having from 3-10 carbon atoms and ethylene makes upat least 85 wt % of the total olefin feed entering the reactor.

In embodiments of the present disclosure, ethylene is copolymerized withpropylene, 1-butene, 1-hexene or 1-octene.

In an embodiment of the present disclosure, ethylene is copolymerizedwith 1-butene and ethylene makes up at least 75 weight % (i.e. wt %) ofthe total olefin feed entering the reactor.

In an embodiment of the present disclosure, ethylene is copolymerizedwith 1-hexene and ethylene makes up at least 75 wt % of the total olefinfeed entering the reactor.

In an embodiment of the present disclosure, ethylene is copolymerizedwith 1-hexene and ethylene makes up at least 85 wt % of the total olefinfeed entering the reactor.

Gas phase fluidized bed polymerization processes may employ a polymerseed bed in the reactor prior to initiating the polymerization process.It is contemplated by the current disclosure to use a polymer seed bedthat has been treated with a catalyst modifier or an optional scavenger(see below). In addition, the polymer products obtained by using thecatalysts and processes of the current disclosure may themselves be usedas polymer seed bed materials.

In an embodiment of the disclosure, a process for polymerizing ethyleneand optionally at least one alpha-olefin to produce an ethylene polymeror copolymer, comprises contacting a spheroidal olefin polymerizationcatalyst with ethylene and optionally at least one alpha-olefin in apolymerization reactor, wherein said spheroidal olefin polymerizationcatalyst has a particle size distribution characterized by a Dm*/Dn ofless than 3.0 and comprises: a phosphinimine catalyst, a cocatalyst, anda spheroidal magnesium chloride support; wherein the magnesium chloridesupport comprises particles with a mass average diameter Dm of 5 to 100μm, a particle size distribution characterized by a Dm/Dn of less than3.0, and comprises less than 2% by weight of an electron donor compound.

Optionally, scavengers are added to the polymerization process. Thepresent disclosure can be carried out in the presence of any suitablescavenger or scavengers. Scavengers are well known in the art.

In an embodiment of the disclosure, scavengers are organoaluminumcompounds having the formula: Al³(X³)_(n)(X⁴)_(3-n), where (X³) is ahydrocarbyl having from 1 to about 20 carbon atoms; (X⁴) is selectedfrom alkoxide or aryloxide, any one of which having from 1 to about 20carbon atoms; halide; or hydride; and n is a number from 1 to 3,inclusive; or alkylaluminoxanes having the formula: R³₂Al¹O(R³Al¹O)_(m)Al¹R³ ₂ wherein each R³ is independently selected fromthe group consisting of C₁₋₂₀ hydrocarbyl radicals and m is from 3 to50. Some non-limiting scavengers useful in the current disclosureinclude triisobutylaluminum, triethylaluminum, trimethylaluminum orother trialkylaluminum compounds.

The scavenger may be used in any suitable amount but by way ofnon-limiting examples only, can be present in an amount to provide amolar ratio of Al:M (where M is the metal of the organometalliccompound) of from about 20 to about 2000, or from about 50 to about1000, or from about 100 to about 500. Generally the scavenger is addedto the reactor prior to the catalyst and in the absence of additionalpoisons and over time declines to 0, or is added continuously.

Optionally, the scavengers may be independently supported. For example,an inorganic oxide that has been treated with an organoaluminum compoundor alkylaluminoxane may be added to the polymerization reactor. Themethod of addition of the organoaluminum or alkylaluminoxane compoundsto the support is not specifically defined and is carried out byprocedures well known in the art.

A “catalyst modifier” is a compound which, when added to apolymerization catalyst system or used in the presence of the same inappropriate amounts, can reduce, prevent or mitigate at least one of:fouling, sheeting, temperature excursions, and static level of amaterial in polymerization reactor; can alter catalyst kinetics; and/orcan alter the properties of copolymer product obtained in apolymerization process.

A long chain amine type catalyst modifier may be added to a reactor zone(or associated process equipment) separately from the polymerizationcatalyst system, as part of the polymerization catalyst system, or bothas described in co-pending CA Pat. Appl. No. 2,742,461. The long chainamine can be a long chain substituted monoalkanolamine, or a long chainsubstituted dialkanolamine as described in co-pending CA Pat. Appl. No.2,742,461, which is incorporated herein in full.

In an embodiment of the disclosure, the catalyst modifier employedcomprises at least one long chain amine compound represented by theformula: R⁹R¹⁰ _(x)N((CH₂)_(n)OH)_(y) where R⁹ is a hydrocarbyl grouphaving from 5 to 30 carbon atoms, R¹⁰ is hydrogen or a hydrocarbyl grouphaving from 1 to 30 carbon atoms, x is 1 or 0, y is 1 when x is 1, y is2 when x is 0, each n is independently an integer from 1 to 30 when y is2, and n is an integer from 1 to 30 when y is 1.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted monoalkanolamine represented by theformula R⁹R¹⁰N((CH₂)_(n)OH) where R⁹ is a hydrocarbyl group havinganywhere from 5 to 30 carbon atoms, R¹⁰ is a hydrogen or a hydrocarbylgroup having anywhere from 1 to 30 carbon atoms, and n is an integerfrom 1-20.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted dialkanolamine represented by theformula: R⁹N((CH₂)_(n)OH)((CH₂)_(m)OH) where R⁹ is a hydrocarbyl grouphaving anywhere from 5 to 30 carbon atoms, and n and m are integers from1-20.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted dialkanolamine represented by theformula: R⁹N((CH₂)_(x)OH)₂ where R⁹ is a hydrocarbyl group havinganywhere from 6 to 30 carbon atoms, and x is an integer from 1-20.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted dialkanolamine represented by theformula: R⁹N((CH₂)_(x)OH)₂ where R⁹ is a hydrocarbyl group havinganywhere from 6 to 30 carbon atoms, and x is 2 or 3.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted dialkanolamine represented by theformula: R⁹N((CH₂)_(x)OH)₂ where R⁹ is a linear hydrocarbyl group havinganywhere from 6 to 30 carbon atoms, and x is 2 or 3.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted dialkanolamine represented by theformula: R⁹N(CH₂CH—₂OH)₂ where R⁹ is a linear hydrocarbyl group havinganywhere from 6 to 30 carbon atoms.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted dialkanolamine represented by theformula: R⁹N(CH₂CH—₂OH)₂ where R⁹ is a linear, saturated alkyl grouphaving anywhere from 6 to 30 carbon atoms.

In an embodiment of the disclosure, the catalyst modifier comprises atleast one long chain substituted dialkanolamine represented by theformula: R⁹N(CH₂CH₂OH)₂ where R⁹ is a hydrocarbyl group having anywherefrom 8 to 22 carbon atoms.

In an embodiment of the disclosure, the catalyst modifier comprises along chain substituted dialkanolamine represented by the formula:C₁₈H₃₇N(CH₂CH₂OH)₂.

In an embodiment of the disclosure, the catalyst modifier comprises longchain substituted dialkanolamines represented by the formulas:C₁₃H₂₇N(CH₂CH₂OH)₂ and C₁₅H₃₁N(CH₂CH₂OH)₂.

In an embodiment of the disclosure, the catalyst modifier comprises amixture of long chain substituted dialkanolamines represented by theformula: R⁹N(CH₂CH₂OH)₂ where R⁹ is a hydrocarbyl group having anywherefrom 8 to 18 carbon atoms.

Non limiting examples of catalyst modifiers which can be used in thepresent disclosure are Kemamine AS-990™, Kemamine AS-650™,Armostat-1800™, bis-hydroxy-cocoamine, 2,2′-octadecyl-amino-bisethanol,and Atmer-163™.

The amount of catalyst modifier added to a reactor (or other associatedprocess equipment) is conveniently represented herein as the parts permillion (ppm) of catalyst modifier based on the weight of copolymerproduced.

The amount of catalyst modifier included in a polymerization catalystsystem is conveniently represented herein as a weight percent (wt %) ofthe catalyst modifier based on the total weight of the polymerizationcatalyst system (e.g. the combined weight of the transition metalcatalyst, the inert support, the cocatalyst and the catalyst modifier).

The catalyst modifier may be added to a polymerization reactor in anumber of ways. The catalyst modifier may be added to a reactor systemseparately from the polymerization catalyst system or it may be combinedwith the polymerization catalyst system prior to feeding the combinationto a reactor system.

If the catalyst modifier is added to the polymerization catalyst systemprior to its addition to a reactor, then the catalyst modifier can beadded at any point during the preparation of the polymerization catalystsystem. Thus, one transition metal catalyst, at least one activator, atleast one inert support and at least one catalyst modifier may becombined in any order to form a polymerization catalyst system suitablefor use in the present disclosure. In some embodiments of thedisclosure: the catalyst modifier may be added to a support after boththe transition metal catalyst and the cocatalyst have been added; thecatalyst modifier may be added to a support before either of thetransition metal catalyst or the cocatalyst are added; the catalystmodifier may be added to a support after the transition metal catalystbut before the cocatalyst; the catalyst modifier may be added to asupport after the cocatalyst but before the transition metal catalyst.Also, the catalyst modifier can be added in portions during any stage ofthe preparation of the polymerization catalyst system.

The catalyst modifier may be included in the polymerization catalystsystem (or where appropriate, added to a polymerization catalyst systemcomponent or components which may comprise one transition metalcatalyst, the inert support and the cocatalyst) in any suitable manner.By way of non-limiting example, the catalyst modifier may be dry blended(if it is a solid) with the polymerization catalyst system (or apolymerization catalyst system component) or it may be added neat (ifthe catalyst modifier is a liquid) or it may be added as solution orslurry in a suitable hydrocarbon solvent or diluent respectively. Thepolymerization catalyst system (or polymerization catalyst systemcomponents) can likewise be put into solution or made into a slurryusing suitable solvents or diluents respectively, followed by additionof the catalyst modifier (as a neat solid or liquid or as a solution ora slurry in suitable solvents or diluents) or vice versa. Alternatively,the catalyst modifier may be deposited onto a separate support and theresulting supported catalyst modifier blended either dry or in a slurrywith the polymerization catalyst system (or a polymerization catalystsystem component).

In an embodiment of the present disclosure, the catalyst modifier isadded to a polymerization catalyst system already comprising the singletransition metal catalyst, inert support and cocatalyst. The catalystmodifier can be added to the polymerization catalyst system offline andprior to addition of the polymerization catalyst system to thepolymerization zone, or the catalyst modifier may be added to thepolymerization catalyst system, or components on route to apolymerization reactor.

The catalyst modifier may be fed to a reactor system using anyappropriate method known to persons skilled in the art. For example, thecatalyst modifier may be fed to a reactor system as a solution or as aslurry in a suitable solvent or diluent respectively. Suitable solventsor diluents are inert hydrocarbons well known to persons skilled in theart and generally include aromatics, paraffins, and cycloparaffinicssuch as for example benzene, toluene, xylene, cyclohexane, fuel oil,isobutane, mineral oil, kerosene and the like. Further examples includebut are not limited to hexane, heptanes, isopentane and mixturesthereof. Alternatively, the catalyst modifier may be added to an inertsupport material and then fed to a polymerization reactor as a dry feedor a slurry feed. The catalyst modifier may be fed to various locationsin a reactor system. When considering a fluidized bed process forexample, the catalyst modifier may be fed directly to any area of thereaction zone (for example, when added as a solution), or any area ofthe entrainment zone, or it may be fed to any area within the recycleloop, where such areas are found to be effective sites at which to feeda catalyst modifier.

When added as a solution or mixture with a solvent or diluentrespectively, the catalyst modifier may make up, for example, from 0.1to 30 wt % of the solution or mixture, or from 0.1 to 20 wt %, or from0.1 to 10 wt %, or from 0.1 to 5 wt % or from 0.1 to 2.5 wt % or from0.2 to 2.0 wt %, although a person skilled in the art will recognizethat further, possibly broader ranges, may also be used and so thedisclosure should not be limited in this regard.

The catalyst modifier can be added to a reactor with all or a portion ofone or more of the monomers or the cycle gas.

The catalyst modifier can be added to a reactor through a dedicated feedline or added to any convenient feed stream including an ethylene feedstream, a comonomer feed stream, a catalyst feed line or a recycle line.

The catalyst modifier can be fed to a location in a fluidized bed systemin a continuous or intermittent manner.

In an embodiment of the disclosure, the rate of addition of a catalystmodifier to a reactor will be programmed using measured reactor staticlevels (or other lead indicators such as reactor temperature) asprogramming inputs, so as to maintain a constant or pre-determined levelof static (or for example, temperature) in a polymerization reactor.

The catalyst modifier can be added to a reactor at a time before, afteror during the start of the polymerization reaction.

The catalyst modifier may be added to the polymerization catalyst systemor to one or more polymerization catalyst system components (e.g. aphosphinimine catalyst, inert support, or cocatalyst) on route to areaction zone.

In an embodiment of the disclosure, the catalyst modifier is addeddirectly to a reaction zone, separately from the polymerization catalystsystem. Most typically, it is so added by spraying a solution or mixtureof the catalyst modifier directly into a reaction zone.

In an embodiment of the disclosure, the catalyst modifier is included(combined) with the polymerization catalyst system before adding thecombination directly to a reaction zone.

In an embodiment of the disclosure, the catalyst modifier is added to apolymer seed bed present in a reactor prior to starting thepolymerization reaction by introduction of a catalyst.

In an embodiment of the disclosure, the catalyst modifier is addeddirectly to a reaction zone, separately from a polymerization catalystsystem, and the catalyst modifier is added as a mixture with an inerthydrocarbon.

In an embodiment of the disclosure, the catalyst modifier is addeddirectly to a reaction zone, separately from a polymerization catalystsystem, and the catalyst modifier is added as a mixture with an inerthydrocarbon, and is added during a polymerization reaction.

The total amount of catalyst modifier that may be fed to a reactorand/or included in the polymerization catalyst system is notspecifically limited, but it should not exceed an amount which causesthe organotransition metal based polymerization catalyst system activityto drop to below that which would be commercially acceptable.

In this regard, the amount of catalyst modifier fed to a reactor willgenerally not exceed about 150 ppm, or 100 ppm, or 75 ppm, or 50 ppm, or25 ppm (parts per million based on the weight of the (co)polymer beingproduced) while the amount of catalyst modifier included in thepolymerization catalyst system will generally not exceed about 10 weightpercent (based on the total weight of the polymerization catalystsystem, including the catalyst modifier).

In embodiments of the disclosure, the catalyst modifier fed to a reactorwill be from 150 to 0 ppm, and including narrower ranges within thisrange, such as but not limited to, from 150 to 1 ppm, or from 150 to 5ppm, or from 100 to 0 ppm, or from 100 to 1 ppm, or from 100 to 5 ppm,or from 75 to 0 ppm, or from 75 to 1 ppm, or from 75 to 5 ppm, or from50 to 0 ppm, or from 50 to 1 ppm, or from 50 to 5 ppm, or from 25 to 0ppm, or from 25 to 1 ppm, or from 25 to 5 ppm (parts per million byweight of the polymer being produced).

In embodiments of the disclosure, the amount of catalyst modifierincluded in the polymerization catalyst system will be from 0 to 10weight percent, and including narrower ranges within this range, such asbut not limited to, from 0 to 6.0 weight percent, or from 0.25 to 6.0weight percent, or from 0 to 5.0 weight percent, or from 0.25 to 5.0weight percent, or from 0 to 4.5 weight percent, or from 0.5 to 4.5weight percent, or from 1.0 to 4.5 weight percent, or from 0.75 to 4.0weight percent, or from 0 to 4.0 weight percent, or from 0.5 to 4.0weight percent, or from 1.0 to 4.0 weight percent, or from 0 to 3.75weight percent, or from 0.25 to 3.75 weight percent, or from 0.5 to 3.5weight percent, or from 1.25 to 3.75 weight percent, or from 1.0 to 3.5weight percent, or from 1.5 to 3.5 weight percent, or from 0.75 to 3.75weight percent, or from 1.0 to 3.75 weight percent (wt % is the weightpercent of the catalyst modifier based on the total weight of thepolymerization catalyst system; e.g. the combined weight of anorganotransition metal catalyst, an inert support, a catalyst activatorand a catalyst modifier).

Other catalyst modifiers may be used in the present disclosure andinclude compounds such as carboxylate metal salts (see U.S. Pat. Nos.7,354,880; 6,300,436; 6,306,984; 6,391,819; 6,472,342 and 6,608,153 forexamples), polysulfones, polymeric polyamines and sulfonic acids (seeU.S. Pat. Nos. 6,562,924; 6,022,935 and 5,283,278 for examples).Polyoxyethylenealkylamines, which are described in for example inEuropean Pat. Appl. No. 107,127, may also be used. Further catalystmodifiers include aluminum stearate and aluminum oleate. Catalystmodifiers are supplied commercially under the trademarks OCTASTAT™ andSTADIS™. The catalyst modifier STADIS is described in U.S. Pat. Nos.7,476,715; 6,562,924 and 5,026,795 and is available from Octel Starreon.STADIS generally comprises a polysulfone copolymer, a polymeric amineand an oil soluble sulfonic acid.

Commercially available catalyst modifiers sometimes contain unacceptableamounts of water for use with polymerization catalysts. Accordingly, thecatalyst modifier may be treated with a substance which removes water(e.g. by reaction therewith to form inert products, or adsorption orabsorption methods), such as a metal alkyl scavenger or molecularsieves. See for example, U.S. Pat. Appl. Pub. No. 2011/0184124 for useof a scavenger compound to remove water from a metal carboxylateantistatic agent. Alternatively, a catalyst modifier may be dried underreduced pressure and elevated temperatures to reduce the amount of waterpresent (see the Examples section below). For example, a catalystmodifier may be treated with elevated temperatures (e.g. at least 10° C.above room temperature or ambient temperature) under reduced pressure(e.g. below atmospheric pressure) to distill off water, as can beachieved by using a dynamic vacuum pump.

In the present disclosure, the term “ethylene copolymer” is usedinterchangeably with the term “copolymer”, or “polyethylene copolymer”and the like, and all connote a polymer consisting of polymerizedethylene units and at least one type of polymerized alpha olefin.

In an embodiment, the polymer is a copolymer of ethylene and at leastone alpha-olefin.

In an embodiment, the polyethylene polymer is a copolymer of ethyleneand at least one alpha-olefin chosen from propylene, 1-butene, 1-hexeneand 1-octene.

In embodiments, polyethylene copolymer composition will comprise atleast 75 weight % of ethylene units, or at least 80 wt % of ethyleneunits, or at least 85 wt % of ethylene units with the balance being analpha-olefin unit, based on the weight of the ethylene copolymercomposition.

In an embodiment of the disclosure, the ethylene copolymer will have adensity of from 0.910 g/cm³ to 0.936 g/cm³. In an embodiment of thedisclosure, the ethylene copolymer will have a density of from 0.910g/cm³ to 0.930 g/cm³. In an embodiment, the ethylene copolymer has adensity of from 0.913 g/cm³ to 0.930 g/cm³. In further embodiments, theethylene copolymer will have a density of from 0.915 g/cm³ to 0.930g/cm³, or from 0.916 g/cm³ to 0.930 g/cm³, or from 0.916 g/cm³ to 0.925g/cm³, or from 0.916 g/cm³ to 0.920 g/cm³, or from 0.917 g/cm³ to 0.927g/cm³, or from 0.917 g/cm³ to 0.920 g/cm³, or from 0.917 g/cm³ to 0.919g/cm³.

In embodiment, the ethylene copolymer has a melt index of from 0.1 to 5g/10 min.

In embodiments of the disclosure, the ethylene copolymer will have amelt index of from 0.3 to 5 g/10 min, or from 0.3 to 3 g/10 min, or from0.5 to 2 g/10 min. In embodiments of the disclosure, the ethylenecopolymer will have a melt index of from 0.1 to 5.0 g/10 min, or from0.25 to 5.0 g/10 min, or from 0.25 to 4.5 g/10 min, or from 0.25 to 4.0g/10 min, or from 0.25 to 3.5 g/10 min, or from 0.25 to 3.0 g/10 min, orfrom 0.75 to 5.0 g/10 min, or from 0.75 to 4.5 g/10 min, or from 0.75 to4.0 g/10 min, or from 0.75 to 3.5 g/10 min, or from 0.25 to 3 g/10 min,or from 0.25 to 2.5 g/10 min, or from 0.5 to 2.0 g/10 min, or from 0.75to 1.5 g/10 min.

In alternate embodiments, the polyethylene copolymer has a melt index(I₂) of from 0.01 to 3.0 g/10 min, or from 0.1 to 2.5 g/10 min, or from0.1 to 2.0 g/10 min, or from 0.25 to 2.0 g/10 min, or from 0.01 to 1.0g/10 min, or from 0.1 to 1.0 g/10 min, or less than 1.0 g/10 min, orfrom 0.1 to less than 1.0 g/10 min, or from 0.25 to 1.0 g/10 min, orfrom 0.25 to 0.9 g/10 min, or from 0.25 to 0.80 g/10 min, or from 0.2 to0.9 g/10 min, or from 0.20 to 0.85 g/10 min, or from 0.25 to 0.85 g/10min.

In embodiments, the polyethylene copolymer will have a melt index ratio(I₂₁/I₂) of less than 20, or less than 18, or less than 17, or less than16.5. In further embodiments, the polyethylene copolymer will have anI₂₁/I₂ of from 10 to 19.5, or from 11 to 19, or from 14 to 19, or from13 to 17, or from 14 to 16.5, or from 14 to 16.0.

In alternative embodiments, the ethylene copolymer will have a meltindex ratio (I₂₁/I₂) of greater than 20 or greater than 24, or greaterthan 26, or greater than 28. In further embodiments the polyethylenecopolymer will have a melt index ratio of from 28 to 60 or from 30 to 60or from 32 to 60, or from 30 to 55, or from 30 to 50, or from 30 to 45,or from 32 to 50 or from 35 to 55, or from 36 to 50, or from 36 to 48,or from 36 to 46, or from 35 to 50, or from greater than 35 to less than50, or from greater than 35 to 50.

In embodiments of the disclosure, the ethylene copolymer will exhibit aweight average molecular weight (M_(w)) as determined by gel permeationchromatography (GPC) of from 30,000 to 250,000, including narrowerranges within this range, such as for example, from 50,000 to 200,000,or from 50,000 to 175,000, or from 75,000 to 150,000, or from 80,000 to130,000.

In embodiments of the disclosure, the ethylene copolymer will exhibit anumber average molecular weight (M_(n)) as determined by gel permeationchromatography (GPC) of from 5,000 to 100,000 including narrower rangeswithin this range, such as for example from 7,500 to 100,000, or from7,500 to 75,000, or from 7,500 to 50,000, or from 10,000 to 100,000, orfrom 10,000 to 75,000, or from 10,000 to 50,000.

In embodiments of the disclosure, the ethylene copolymer will exhibit aZ-average molecular weight (M_(z)) as determined by gel permeationchromatography (GPC) of from 50,000 to 2,000,000, including narrowerranges within this range, such as for example from 50,000, to 1,750,000,or from 50,000 to 1,500,000, or from 50,000 to 1,000,000, or from 75,000to 750,000, or from 100,000 to 500,000, or from 100,000 to 400,000, orfrom 125,000 to 375,000, or from 150,000 to 350,000, or from 175,000 to375,000, or from 175,000 to 400,000, or from 200,000 to 400,000 or from225,000 to 375,000.

In embodiments, the ethylene copolymer will have a molecular weightdistribution (M_(w)/M_(n)) as determined by gel permeationchromatography (GPC) of from 1.6 to 2.6, or from 1.7 to 2.5, or from 1.7to 2.4, or from 1.7 to 2.3, or from 1.7 to 2.2, or from 1.8 to 2.4, orfrom 1.8 to 2.3, or from 1.8 to 2.2.

In yet another embodiment of the disclosure, the ethylene copolymer willhave a molecular weight distribution (M_(w)/M_(n)) of ≤2.5. In stillanother embodiment of the disclosure, the ethylene copolymer will have amolecular weight distribution (M_(w)/M_(n)) of ≤2.4. In yet anotherembodiment of the disclosure, the ethylene copolymer will have amolecular weight distribution (M_(w)/M_(n)) of ≤2.3. In yet furtherembodiments of the disclosure, the ethylene copolymer will have amolecular weight distribution (M_(w)/M_(n)) of ≤2.2, or ≤2.1, or ≤2.0.

In alternative embodiments, polyethylene copolymer will have a molecularweight distribution (M_(w)/M_(n)) as determined by gel permeationchromatography (GPC) of from 3.5 to 7.0, including narrower rangeswithin this range, such as for example, from 3.5 to 6.5, or from 3.6 to6.5, or from 3.6 to 6.0, or from 3.5 to 5.5, or from 3.6 to 5.5, or from3.5 to 5.0, or from 4.5 to 6.0, or from 4.0 to 6.0, or from 4.0 to 5.5.

In an embodiment, the polyethylene copolymer will have a flat comonomerincorporation profile as measured using Gel-Permeation Chromatographywith Fourier Transform Infra-Red detection (GPC-FTIR). In an embodiment,the polyethylene copolymer will have a negative (i.e. “normal”)comonomer incorporation profile as measured using GPC-FTIR. In anembodiment, the polyethylene copolymer will have an inverse (i.e.“reverse”) or partially inverse comonomer incorporation profile asmeasured using GPC-FTIR. If the comonomer incorporation decreases withmolecular weight, as measured using GPC-FTIR, the distribution isdescribed as “normal” or “negative”. If the comonomer incorporation isapproximately constant with molecular weight, as measured usingGPC-FTIR, the comonomer distribution is described as “flat” or“uniform”. The terms “reverse comonomer distribution” and “partiallyreverse comonomer distribution” mean that in the GPC-FTIR data obtainedfor the copolymer, there is one or more higher molecular weightcomponents having a higher comonomer incorporation than in one or morelower molecular weight segments. The term “reverse(d) comonomerdistribution” is used herein to mean, that across the molecular weightrange of the ethylene copolymer, comonomer contents for the variouspolymer fractions are not substantially uniform and the higher molecularweight fractions thereof have proportionally higher comonomer contents(i.e. if the comonomer incorporation rises with molecular weight, thedistribution is described as “reverse” or “reversed”). Where thecomonomer incorporation rises with increasing molecular weight and thendeclines, the comonomer distribution is still considered “reverse”, butmay also be described as “partially reverse”.

The spheroidal magnesium chloride supported phosphinimine catalystsdescribed herein generally provides polyethylene polymers of greaterhomogeneity than silica supported phosphinimine catalysts.

In embodiments of the disclosure, the ethylene copolymer will have acomonomer distribution breadth index (CDBI₅₀), as determined bytemperature elution fractionation (TREF), of at least 40 weight percent(wt %), or at least 50 wt %, or at least 60 wt %, or at least 65 wt %,or at least 70 wt %, or at least 75 wt %. In further embodiments of thedisclosure, the ethylene copolymer will have a comonomer distributionbreadth index (CDBI₅₀), as determined by temperature elutionfractionation (TREF) of from 40 wt % to 85 wt %, or from 45 wt % to 85wt %, or from 50 wt % to 85 wt %, or from 55 wt % to 80 wt %, or from 60wt % to 80 wt %, or from 60 wt % to 75 wt %, or from 65 wt % to 75 wt %.

In embodiment of the disclosure, a polyethylene copolymer having a meltindex ratio (I₂₁/I₂) of less than 20 will have a comonomer distributionbreadth index (CDBI₅₀) of greater than 55 weight percent, or greaterthan 60 weight percent, or greater than 65 weight percent, or greaterthan 70 weight percent, or greater than 75 weight percent.

In alternative embodiment of the disclosure, a polyethylene copolymerhaving a melt index ratio (I₂₁/I₂) of greater than 20 will have acomonomer distribution breadth index (CDBI₅₀) of greater than 50 weightpercent, or greater than 55 weight percent, or greater than 60 weightpercent, or greater than 65 weight percent.

In embodiment of the disclosure, a polyethylene copolymer having a meltindex ratio (I₂₁/I₂) of less than 20 will have less than 20 weightpercent, or less than 15 weight percent, or less than 10 weight percent,or less than 5 weight percent of the polyethylene represented within atemperature range of from 90° C. to 105° C. in a TREF profile.

In an alternative embodiment of the disclosure, a polyethylene copolymerhaving a melt index ratio (I₂₁/I₂) of greater than 20 will have lessthan 20 weight percent, or less than 15 weight percent, or less than 10weight percent, or less than 5 weight percent of the polyethylenerepresented within a temperature range of from 90° C. to 105° C. in aTREF profile.

In an embodiment of the disclosure, a polyethylene copolymer comprisingat least 75 wt % of ethylene units with the balance being alpha-olefinunits, will have a density of from 0.910 g/cm³ to 0.936 g/cm³, aspheroidal particle shape and a particle size distribution characterizedby a Dm*/Dn of less than 3.0.

In an embodiment of the disclosure, a polyethylene copolymer comprisingat least 75 wt % of ethylene units with the balance being alpha-olefinunits, will have a density of from 0.910 g/cm³ to 0.936 g/cm³, aspheroidal particle shape and a particle size distribution characterizedby a Dm*/Dn of less than 2.5.

In an embodiment of the disclosure, a polyethylene copolymer comprisingat least 75 wt % of ethylene units with the balance being alpha-olefinunits, will have a density of from 0.910 g/cm³ to 0.936 g/cm³, aspheroidal particle shape and a particle size distribution characterizedby a Dm*/Dn of less than 2.0.

In an embodiment of the disclosure, a polyethylene copolymer comprisingat least 75 wt % of ethylene units with the balance being alpha-olefinunits, will have a density of from 0.910 g/cm³ to 0.936 g/cm³, aspheroidal particle shape and a particle size distribution characterizedby a Dm*/Dn of less than 1.5.

In an embodiment of the disclosure, a polyethylene copolymer comprisingat least 75 wt % of ethylene units with the balance being alpha-olefinunits, will have a density of from 0.910 g/cm³ to 0.936 g/cm³, aspheroidal particle shape, and a particle size distributioncharacterized by a Dm*/Dn of less than 3.0; wherein the polyethylene ismade with a spheroidal olefin polymerization catalyst having a particlesize distribution characterized by a Dm*/Dn of less than 3.0, andcomprising: a phosphinimine catalyst, a cocatalyst, and a spheroidalmagnesium chloride support; wherein the magnesium chloride supportcomprises particles with a mass average diameter Dm of 5 to 100 μm, aparticle size distribution characterized by a Dm/Dn of less than 3.0,and comprises less than 2% by weight of an electron donor compound.

The present disclosure will now be further illustrated by the followingnon limiting examples.

EXAMPLES Reagents

Diethylaluminum Chloride (97%) was purchased from Sigma Aldrich and wasstored in a flammable cabinet prior to use. It was brought in to theglovebox and transferred into a hypovial immediately prior to use. Usedas received.

Dibutylmagnesium as a 1M solution in heptane was purchased from SigmaAldrich. Upon arrival the bottles were transferred to the glovebox whereit was stored under a nitrogen atmosphere in the freezer (at −30° C.).It was used as received.

Diisoamyl ether was purchased from Sigma Aldrich and transferred intothe glovebox upon arrival. It was then stored in the freezer at −30° C.prior to use.

A drying reagent (Drierite™ was purchased from Sigma Aldrich. The dryingreagent was conditioned before use by baking it in a muffle furnace setto 260° C. for a period of 16 hours. The drying reagent contained noindicator.

2-chloro-2-methylpropane (tert-butyl chloride or tBuCl) was purchasedfrom Sigma Aldrich. The tBuCl was dried by placing it over the pre-drieddrying reagent under an inert environment for approximately 16 hours ata ratio of 30 g of drying reagent per 100 mL of tBuCl. The flaskcontaining the tBuCl was covered in foil to shield it from light duringthis process to minimize the formation of isobutylene. The dried tBuClwas further purified by vacuum transfer. The tBuCl moisture content was12 ppm or less and had purity above 97% after purification. Allglassware used in this procedure was dried in a 130° C. oven overnight.

Heptane was purchased from Sigma Aldrich and further purified using withalumina and molsieve columns. It was stored in the glovebox in Nalgenebottles containing 13× molecular sieves to dry (99.9% purity).

Methylaluminoxane (MAO) was used as a 30% MAO solution (13.1 wt Al) oras a 10% MAO solution 4.5 wt % Al) in toluene purchased from Albemarle.

The silica support for the comparative examples was Sylopol® 2408purchased from Grace Davidson. The silica had a particle size from 12 to76 μm and a pore volume of about 1.52 cc/gm.

Analytical Measurements

Scanning Electron Microscope:

For the examination of MgCl₂ particles, in order to obtain the massaverage diameter (Dm) and the number average diameter (Dn), a numberweighted particle size distribution was measured by electron microscopyvia automated binary threshold particle recognition analysis. Thisanalysis was performed with backscattered electron detected imagesobtained via a scanning electron microscope (SEM, manufacturer Hitachi“S-3400N II”) equipped with an energy dispersive spectrometer (EDS,manufacturer Oxford Instruments “X-sight 450”). Oxford Instruments“INCA” software is capable of automated particle analysis via thresholdparticle acquisition, which is based on the principle that the particlesor ‘features’ are recognized against a background matrix, forming abinary image where particles are recognized via a selected thresholdsignal level. The acquisition process is automated over a specifiedregion where the particles have been applied to a suitable matrix(carbon tape) such that particle-to-particle touching is minimized sothat particle recognition is primarily on discrete particles surroundedby the matrix background. During acquisition, both EDS spectra andparticle morphological data are acquired simultaneously for bothelemental composition and particle morphology for each recognizedparticle is recorded. The conditions used for measurement were asfollows: 20 kV, aperture 1, 10 mm working distance, probe current 50-70setting, 700× magnification field-of-view, back scattered electrondetector, with a minimum of 700 particles detected.

During post-acquisition, a morphological and compositional filter wasapplied to remove anomalous data (non MgCl₂ particles) by the followingcriteria: particle area 150≤x≤825 μm, aspect ratio 1≤x≤2.25, excludingparticles detecting Fe, Ni, Cr. The particles passing through thesefilter criteria were used for analysis.

Stereomicroscope:

A Carl Zeiss stereomicroscope Model #47 50 03-9901 adapted with aphotographic camera was used for showing the spheroidal shape of theMgCl₂ support particles, the polymerization catalyst particles as wellas the product ethylene copolymer particles. All the polymerizationcatalyst and polymer particle spheroidal shapes and uniformities weredetermined by pictures taken from this instrument.

Determination of Particle Size Distribution:

The mass average diameter (Dm) (or the “relative mass average diameter(Dm*)) and the number average diameter (Dn) of the support, olefinpolymerization catalyst and polymer particles are determined on thebasis of microscopic observations. The particle size distribution thenmay be characterized by Dm/Dn. For a means of determining Dm, Dn, andhence Dm/Dn, see CA Pat. No. 1,189,053 and U.S. Pat. No. 5,106,804. Theparticle size distribution may also be characterized by Dm*/Dn asdefined below.

By obtaining by optical microscopy of a population of particles, such asa population of magnesium chloride particles, a table of absolutefrequencies showing the number n_(i) of particles belonging to eachclass i of diameters, where each class i is characterized by anintermediate diameter d_(i), between the limits of each class, isobtained. Dm and Dn then are determined using the following equations:mass average diameter, Dm=Σn_(i)(d_(i))³d_(i)/Σn_(i)(d_(i))³; numberaverage diameter, Dn=Σn_(i) d_(i)/Σn_(i). The ratio, Dm/Dn defines theparticle size distribution, and is sometimes known as the “width of theparticle size distribution”. The particle size distribution can be alsobe characterized by taking a unit-less “relative mass average diameter”defined as Dm* over a number average diameter Dn, where the Dm* isobtained by visual examination of particle sizes of varying relativediameter and counting the number of particles in each particle diametergroup or class. This allows a person skilled in the art to characterizethe particle size distribution using optical equipment which does notprovide an absolute value (e.g. in microns) for the mass averagediameter, Dm*.

Thermogravimetric analysis was coupled with Fourier transform infraredspectrometry to provide a weight loss profile and qualitativeidentification of the evolved gases as a sample is heated in an inertatmosphere (UHP nitrogen). The analytical instruments used are a TAInstruments SDT2960 thermal analyzer and a Bruker Tensor 27 FTIRspectrometer. The following temperature program was used for the thermalanalysis: ramp at 5° C./minute to 115° C. and hold at 115° C. for 15minutes; ramp at 10° C./minute to 200° C. and hold at 200° C. for 30minutes. The weight loss during the ramp to 115° C. and the 115° C. holdtime is usually attributable to the loss of the solvent used during thepolymerization catalyst or MgCl₂ support preparation process. Examplesof the typical solvents used are toluene, isoamyl ether, heptane, andTHF. The weight loss during the ramp to 200° C. and the 200° C. holdtime is attributable to the loss of further solvent. The lack of solventin the evolved gas during this portion of the program is an indicatorthat all of the solvent had evolved during the first portion of theprogram.

Melt index, I₂, in g/10 min was determined on a Tinius Olsen Plastomer(Model MP993) in accordance with ASTM D1238 condition F at 190° C. witha 2.16 kilogram weight. Melt index, I₁₀, was determined in accordancewith ASTM D1238 condition F at 190° C. with a 10 kilogram weight. Highload melt index, I₂₁, in g/10 min was determined in accordance with ASTMD1238 condition E at 190° C. with a 21.6 kilogram weight.

Polymer density was determined in grams per cubic centimeter (g/cc)according to ASTM D792.

Molecular weight information (M_(w), M_(n) and M_(z) in g/mol) andmolecular weight distribution (M_(w)/M_(n)), and z-average molecularweight distribution (Mz/Mw) were analyzed by gel permeationchromatography (GPC), using an instrument sold under the trade name“Waters 150c”, with 1,2,4-trichlorobenzene as the mobile phase at 140°C. The samples were prepared by dissolving the polymer in this solventand were run without filtration. Molecular weights are expressed aspolyethylene equivalents with a relative standard deviation of 2.9% forthe number average molecular weight (“Mn”) and 5.0% for the weightaverage molecular weight (“Mw”). Polymer sample solutions (1 to 2 mg/mL)were prepared by heating the polymer in 1,2,4-trichlorobenzene (TCB) androtating on a wheel for 4 hours at 150° C. in an oven. The antioxidant2,6-di-tert-butyl-4-methylphenol (BHT) was added to the mixture in orderto stabilize the polymer against oxidative degradation. The BHTconcentration was 250 ppm. Sample solutions were chromatographed at 140°C. on a PL 220 high-temperature chromatography unit equipped with fourShodex columns (HT803, HT804, HT805 and HT806) using TCB as the mobilephase with a flow rate of 1.0 mL/minute, with a differential refractiveindex (DRI) as the concentration detector. BHT was added to the mobilephase at a concentration of 250 ppm to protect the columns fromoxidative degradation. The sample injection volume was 200 mL. The rawdata were processed with Cirrus GPC software. The columns werecalibrated with narrow distribution polystyrene standards. Thepolystyrene molecular weights were converted to polyethylene molecularweights using the Mark-Houwink equation, as described in the ASTMstandard test method D6474.

The peak melting point (T_(m)) and percent of crystallinity of thepolymers were determined by using a TA Instrument DSC Q1000 ThermalAnalyser at 10° C./min. In a DSC measurement, a heating-cooling-heatingcycle from room temperature to 200° C. or vice versa was applied to thepolymers to minimize the thermo-mechanical history associated with them.The melting point and percent of crystallinity were determined by theprimary peak temperature and the total area under the DSC curverespectively from the second heating data. The peak melting temperatureT_(m) is the higher temperature peak, when two peaks are presented in abimodal DSC profile (typically also having the greatest peak height).

The branch frequency of the polyethylene polymer samples (i.e. the shortchain branching, SCB per 1000 carbons) and the C₆ comonomer content (inwt %) was determined by Fourier Transform Infrared Spectroscopy (FTIR)as per the ASTM D6645-01 method. A Thermo-Nicolet 750 Magna-IRSpectrophotometer equipped with OMNIC version 7.2a software was used forthe measurements.

The determination of branch frequency as a function of molecular weight(and hence the comonomer distribution profile) was carried out usinghigh temperature Gel Permeation Chromatography (GPC) and FT-IR of theeluent. Polyethylene standards with a known branch content, polystyreneand hydrocarbons with a known molecular weight were used forcalibration.

To determine CDBI₅₀, a solubility distribution curve is first generatedfor the copolymer. This is accomplished using data acquired from theTREF technique. This solubility distribution curve is a plot of theweight fraction of the copolymer that is solubilized as a function oftemperature. This is converted to a cumulative distribution curve ofweight fraction versus comonomer content, from which the CDBI₅₀ isdetermined by establishing the weight percentage of a copolymer samplethat has a comonomer content within 50% of the median comonomer contenton each side of the median. The weight percentage of a higher densityfraction, (i.e. the wt % eluting from 90-105° C.), is determined bycalculating the area under the TREF curve at an elution temperature offrom 90 to 105° C. The weight percent of copolymer eluting below 40° C.can be similarly determined. For the purpose of simplifying thecorrelation of composition with elution temperature, all fractions areassumed to have a Mn≥15,000, where Mn is the number average molecularweight of the fraction. Any low molecular weight fractions presentgenerally represent a trivial portion of the polymer. The remainder ofthis description maintains this convention of assuming all fractionshave Mn≥15,000 in the CDBI₅₀ measurement.

Temperature rising elution fractionation (TREF) method. Polymer samples(50 to 150 mg) were introduced into the reactor vessel of acrystallization-TREF unit (Polymer ChAR™). The reactor vessel was filledwith 20 to 40 ml 1,2,4-trichlorobenzene (TCB), and heated to the desireddissolution temperature (e.g. 150° C.) for 1 to 3 hours. The solution(0.5 to 1.5 ml) was then loaded into the TREF column filled withstainless steel beads. After equilibration at a given stabilizationtemperature (e.g. 110° C.) for 30 to 45 minutes, the polymer solutionwas allowed to crystallize with a temperature drop from thestabilization temperature to 30° C. (0.1 or 0.2° C./minute). Afterequilibrating at 30° C. for 30 minutes, the crystallized sample waseluted with TCB (0.5 or 0.75 mL/minute) with a temperature ramp from 30°C. to the stabilization temperature (0.25 or 1.0° C./minute). The TREFcolumn was cleaned at the end of the run for 30 minutes at thedissolution temperature. The data were processed using Polymer ChARsoftware, Excel spreadsheet and TREF software developed in-house.

The TREF procedure described above is well known to persons skilled inthe art and can be used to determine: the overall TREF profile, CDBI₅₀,the polyethyelene polymer wt % represented at from 90° C. to 105° C.

Preparation of the Phosphinimine Catalysts

All reactions involving air and or moisture sensitive compounds wereconducted under nitrogen using standard Schlenk and cannula techniques,or in a glovebox. Reaction solvents were purified either using thesystem described by Pangborn et. al. in Organometallics 1996, v15, p.1518 or used directly after being stored over activated 4 Å molecularsieves. The aluminoxane used was a 10% MAO solution in toluene suppliedby Albemarle which was used as received. The phosphinimine catalystcompound (1,2-(n-propyl)(C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂ was made in a mannersimilar to the procedure given in U.S. Pat. No. 7,531,602 (see Example2). The phosphinimine compound (1-C₆F₅CH₂-Indenyl)((t-Bu)₃P═N)TiCl₂ wasmade as follows. To distilled indene (15.0 g, 129 mmol) in heptane (200mL) was added BuLi (82 mL, 131 mmol, 1.6 M in hexanes) at roomtemperature. The resulting reaction mixture was stirred overnight. Themixture was filtered and the filter cake washed with heptane (3×30 mL)to give indenyllithium (15.62 g, 99% yield). Indenyllithium (6.387 g,52.4 mmol) was added as a solid over 5 minutes to a stirred solution ofC₆F₅CH₂—Br (13.65 g, 52.3 mmol) in toluene (100 mL) at room temperature.The reaction mixture was heated to 50° C. and stirred for 4 h. Theproduct mixture was filtered and washed with toluene (3×20 mL). Thecombined filtrates were evaporated to dryness to afford 1-C₆F₅CH₂-indene(13.58 g, 88%). To a stirred slurry of TiCl₄.2THF (1.72 g, 5.15 mmol) intoluene (15 mL) was added solid (t-Bu)₃P═N—Li (1.12 g, 5 mmol) at roomtemperature. The resulting reaction mixture was heated at 100° C. for 30min and then allowed to cool to room temperature. This mixturecontaining ((t-Bu)₃P═N)TiCl₃ (1.85 g, 5 mmol) was used in the nextreaction. To a THF solution (10 mL) of 1-C₆F₅CH₂-indene (1.48 g, 5 mmol)cooled at −78° C. was added n-butyllithium (3.28 mL, 5 mmol, 1.6 M inhexanes) over 10 minutes. The resulting dark orange solution was stirredfor 20 minutes and then transferred via a double-ended needle to atoluene slurry of ((t-Bu)₃P═N)TiCl₃ (1.85 g, 5 mmol). The cooling wasremoved from the reaction mixture which was stirred for a further 30minutes. The solvents were evaporated to afford a yellow pasty residue.The solid was re-dissolved in toluene (70 mL) at 80° C. and filteredhot. The toluene was evaporated to afford pure(1-C₆F₅CH₂-Indenyl)((t-Bu)₃P═N)TiCl₂ (2.35 g, 74%).

Preparation of Spheroidal MgCl₂ Support

A bench scale reactor was used for the preparation of MgCl₂: a 2 Lstirred Parr bench-scale reactor was used. The reactor was equipped witha mechanical stir capable of stirring to 1200 rpm. The jacketed reactorhad a temperature control system to maintain the reactor temperaturebetween 30 to 100° C. The reactor was equipped with a triple blade metalstirrer, baffles and pressurized to 5 psi nitrogen. The reactor was thencharged with a 1M solution of dibutyl magnesium in heptane (417.5 mL,417.5 mmol), diisoamyl ether (31.9 g, 201.2 mmol) and anhydrous heptane(275 mL). Stirring was started at 1191 rpm. Next,2-methyl-2-chloropropane (115.7 g, 1250 mmol) in anhydrous heptane (125mL) was added via syringe pump at a constant rate over 7 hours. Afterthe addition was complete the mixture was stirred at 1191 rpm overnight.The white mixture was transferred out of the reactor to a glass vesselwhere the mother liquor was decanted and the remaining white solids werewashed six times with pentane and dried to 300 mTorr via vacuum.Yield=50.465 g. A scanning electron micrograph (SEM) of the magnesiumsupport is provided in FIG. 1. FIG. 1 shows that the magnesium chloridesupport particles have a spheroidal shape. The magnesium chloridesupport particles have an average diameter in the range of 20 μm to 30μm and a Dm/Dn value of 1.07 with Dm=28.4 μm and Dn=26.6.

For the MgCl₂ support particles, both the mass average diameter D_(m)(by SEM) and the “relative” mass average diameter D_(m)* (bystereomicroscope) were obtained to provide a comparison of the methods.Based on SEM, 347 particles were counted. They were divided into 7different classes with 5 micron intervals from 15 to 50 microns. D_(m)and D_(n) were calculated based on data in the Table 1A below.

TABLE 1A Diameter Lower Upper in limit in limit in microns micronsmicrons (μm) (μm) (μm) Count 17.5 15 20 18 22.5 20 25 89 27.5 25 30 18932.5 30 35 42 37.5 35 40 8 42.5 40 45 1 47.5 45 50 0 Dm = 28.4 micronand Dn = 26.6 micron. Dm/Dn = 1.07

The picture obtained from the stereomicroscope showing the dense andspheroidal particles was enlarged for easy counting, so the units of Dm*are arbitrary and have no real meaning; the Dm* is a relative massaverage diameter. Nevertheless, the particle size distributioncharacterized by Dm*/Dn showed similar results to the particle sizedistribution characterized as Dm/Dn and determined by SEM. With thestereomicroscope, a total of 166 particles were counted and Dm*/Dn=1.05.The particle size classes in Table 1B represent different sizecategories for the counted particles.

TABLE 1B Particles Size Class Total size(mm) Class 1 132 10 Class 2 24 8Class 3 2 6 Class 4 4 12 Class 5 4 15

Thermogravimetric analysis (TGA) showed that the spheroidal MgCl₂support contained 9.9% by weight of the diisoamyl ether compound.

Ether Removal Method A) To remove the diisoamyl ether from the magnesiumchloride support, the support was heated in a Schlenk flask undernitrogen at 120° C. for 3 hours and until the final vacuum reading was200 mTorr of vacuum. The amount of ether remaining in the MgCl₂ supportafter heat treatment (in weight percent by weight of support) wascalculated by thermogravimetric analysis (TGA) and is shown in Table 2.A picture of the magnesium support particles shows that good spheroidalmorphology is well maintained after the ether removal step (see FIG. 2).

Ether Removal Method B) Alternatively, the ether could be removed bytreating the spheroidal MgCl₂ support with diethylaluminum chloride(Et₂AlCl or “DEAC”). The ether could be reduced to below 1.5 weightpercent when a molar ratio of Al to ether of 5 to 1 was used. To treatthe MgCl₂, a solution of diethylaluminum chloride was added to the solidsupport and the mixture was agitated for 12 hrs. The amount of etherremaining in the MgCl₂ support after Et₂AlCl (in weight percent byweight of support) was calculated by thermogravimetric analysis (TGA)and is shown in Table 2. It was found that diethylaluminum chloride wasmore effective at reducing the amount of ether present in the MgCl₂support than was triethylaluminum (TEAL) under similar treatmentconditions. Compare catalyst 3, where 2 weight % of the diisoamyl etherremains in the MgCl₂ support, with inventive catalyst 1B, where 1.2weight % of diisoamyl ether remains in the MgCl₂ support (see Table 2).

Preparation of Polymerization Catalysts (Supporting PhosphinimineCatalyst and Cocatalyst on MgCl₂)

Each catalyst was prepared targeting a final formulation having 0.03mmol titanium per gram of catalyst, a molar ratio of Al (from MAO) totitanium of 45:1 (except that for the catalyst 3 where the target wasAl/Ti=15:1), and a molar ratio of magnesium to titanium of about 350:1.The polymerization catalyst particles were examined using astereomicroscope.

Catalyst 1A) 9.11 mg of the phosphinimine catalyst compound,(1,2-(n-propyl) (C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂ was combined with 0.402 g ofa 10 wt % MAO solution in a hypovial. A stir bar was added and themixture was stirred for 30 minutes. The phosphinimine catalyst/MAOsolution was then added to 0.498 g of the MgCl₂ support prepared asabove and using method A to remove the ether (and which MgCl₂ wasslurried in toluene). The hypovial was shaken overnight and the contentswere filtered on a filter frit and washed twice with toluene and threetimes with pentane and then dried to <500 mTorr. The resulting catalysthad a Dm*=9.06, a Dn=8.81 and a Dm*/Dn=1.03. FIG. 3A, which is anexpanded image obtained from stereomicroscopy confirms that thepolymerization catalyst was comprised of particles having a spheroidalshape.

Catalyst 1B) This catalyst was prepared similarly to catalyst 1A exceptthat method B was used to remove the ether from the MgCl₂ support. Theresulting catalyst had a Dm*=7.19, a Dn=7.08 and a Dm*/Dn=1.02. FIG. 3B,which is an expanded image obtained from stereomicroscopy confirms thatthe polymerization catalyst was comprised of particles having aspheroidal shape.

Catalyst 2A) 9.42 mg of the phosphinimine catalyst compound,(1-C₆F₅CH₂-Indenyl)((t-Bu)₃P═N)TiCl₂ was combined with 0.404 g of a 10wt % MAO solution in a hypovial. A stir bar was added and the mixturewas stirred for 30 minutes. The phosphinimine catalyst/MAO solution wasthen added to 0.502 g of the MgCl₂ support prepared as above and usingmethod A to remove the ether (and which MgCl₂ was slurried in toluene).The hypovial was shaken overnight and the contents were filtered on afilter frit and washed twice with toluene and three times with pentaneand then dried to <500 mTorr. The resulting catalyst had a Dm*=9.29, aDn=8.81 and a Dm*/Dn=1.06. FIG. 4A, which is an expanded image obtainedfrom stereomicroscopy confirms that the polymerization catalyst wascomprised of particles having a spheroidal shape.

Catalyst 2B) This catalyst was prepared similarly to catalyst 2A exceptthat method B was used to remove the ether from the MgCl₂ support. Theresulting catalyst had a Dm*=9.036, a Dn=8.81 and a Dm*/Dn=1.03. FIG.4B, which is an expanded image obtained from stereomicroscopy confirmsthat the polymerization catalyst was comprised of particles having aspheroidal shape.

Catalyst 3) This catalyst was prepared similarly to catalyst 1B exceptthat triethylaluminum (TEAL) was used to remove the ether from the MgCl₂support instead of diethylaluminum chloride (DEAC).

Some details of the olefin polymerization catalysts are provided inTable 2. Note that the MgCl₂ supports having less than about 2 weight %of ether present, lead to improved catalyst loading on to the support asindicated by the titanium % by weight of the final catalyst. Below about2 wt % of ether, the weight percent of the phosphinimine catalyst endingup on the support is always above about 50 wt %. Hence, reduction orremoval of the ether compound from the spheroidal magnesium support,once formed, appears to be important for achieving significant loadingof a phosphinimine type catalyst compound onto a spheroidal MgCl₂support.

TABLE 2 Catalyst Composition The MgCl₂ Support Weight % of The FinalCatalyst Composition Ether Present Total Ti (Final wt % of PhosphinimineEther after mmol of (wt % of Phosphinimine Catalyst Removal Treatment(by Ti/g total Catalyst on the Molecule Method TGA) catalyst catalyst)support) 1A, (1,2-(n- Heat 0.075 0.017 0.083 56 propyl)(C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂ 1B, (1,2-(n- Et₂AlCl 1.2 0.021 0.102 71propyl)(C₆F₅)Cp)Ti(N═ P(t-Bu)₃)Cl₂ 2A, (1-C₆F₅CH₂- Heat 0.075 0.0240.113 77 Indenyl)((t- Bu)₃P═N)TiCl₂ 2B C₆F₅CH₂- Et₂AlCl 1.2 0.021 0.11580 Indenyl)((t- Bu)₃P═N)TiCl₂ 3, (1,2-(n- TEAL 2.0 0.013 0.064 44propyl)(C₆F₅)Cp)Ti(N═ P(t-Bu)₃)Cl₂

For comparison purposes the phosphinimine catalyst molecules used tomake inventive catalysts 1A or 1B and 2A or 2B were also supported onsilica. For a general preparation of the silica supported comparativecatalyst 4 which is based on phosphinimine catalyst compound(1,2-(n-propyl)(C₆F₅)Cp)Ti(N═P(t-Bu)₃)Cl₂ see U.S. Pat. Appl. Pub. No.2013/0345377. For a general preparation of the silica supportedcomparative catalyst 5 which is based on phosphinimine catalyst compound(1-C₆F₅CH₂-Indenyl)((t-Bu)₃P═N)TiCl₂ see U.S. Pat. Appl. Pub. No.2013/0345377.

Polymerization

The Bench Scale Reactor (BSR) was a 2 liter autoclave semi batch reactoroperating in the gas phase at 88° C. at 300 psig of total operatingpressure. 1.0 mL of a 25 wt % solution of triisobutylaluminum (TIBAL) inheptane was used as an impurity scavenger prior to introduction ofethylene. Catalyst delivery and polymer removal were in batch mode, andall feed-streams delivery was continuous. The reactor was equipped withimpeller stirrers that spin at 525 rpm to provide reactor mixing. TheBSR was equipped with a process Gas Chromatograph that continuouslymeasures the reactor headspace composition. A syringe pump delivered1-hexene to the reactor and all other feed-streams were delivered viamass flow indicating controllers. The feed-streams responded to inputsfrom the master controller in a closed loop control system to maintainreaction set-points. Feed-stream control utilized cascadedproportional-integral-derivative (i.e. PID) loops for each of thereactor reagents (ethylene, 1-hexene, hydrogen and nitrogen). Theoperator entered the target mole % of each reagent into the HumanMachine Interface. These values were what the primary or master looputilized as the process set-point target and this was what the unitmonitored via the feedback from the process GC analysis. The cascaded(slave) loop interpreted the output from the master loop as a molarratio of the reagent concentration divided by ethylene concentration.This reagent molar ratio varied during the reaction in relation to theGC analysis output concentrations in the master loop and therebymaintained reagent set-points in the master loop. Pressure control ofthe reactor was done by the use of a single PID loop where input to theloop was in the form of the observed reactor pressure. The loop outputcontrolled the flow of only ethylene to the reactor to maintain the setpressure. As described above, all of the other reaction components arefed in ratio to the ethylene and are therefore subject to theconstraints of pressure control.

General Conditions: The reactor was heated at 100° C. for 1 hour andthoroughly purged with nitrogen. A polymerization catalyst (prepared asabove) was loaded into a catalyst injection tube in an inert atmosphereglove box. The catalyst injection tube was attached to the reactor, andthe reactor was purged once with ethylene and four times with nitrogen.Ethylene partial pressure was maintained at 50 mol % in the reactor.1-Hexene partial pressure was maintained at 0.8 mol %. Hydrogen flow wasadjusted to the ethylene flow such that the partial pressure wasmaintained at approximately 0.025 mol % and the balance of the reactormixture (approximately 49 mol %) was nitrogen. The run was continued for60 minutes, before the ethylene flow was stopped. Cooling water wasturned on and the ethylene was slowly vented from the reactor. Thereactor was then purged with nitrogen. The reactor was then opened sothat the reactor contents, the reactor appearance and the polymer couldbe observed. The polymer was removed and then weighed. Polymer data areprovided in Table 3 and FIGS. 5A, 5B, 6A, 6B, 7 and 8.

TABLE 3 Polymer Properties Poly. Run No. 1 2 3 4 5 6 Catalyst 1A 1B 2A2B Comp. 4 Comp. 5 Polymer Spheroidal Spheroidal Spheroidal SpheroidalIrregular Irregular Morphology FIG. 5A FIG. 5B FIG. 6A FIG. 6B FIG. 7FIG. 8 Dm*/Dn — 1.05 1.03 — — — Density 0.9111 0.9107 0.9166 0.92380.9152 0.9182 (g/cc) I₂ (g/10 min) 1.01 1.06 0.44 0.37 1.44 0.66 I₂₁17.3 23.2 16 21.4 24.7 22.8 I₂₁/I₂ 17.2 22 36.2 59 17.1 35.9 CDBI₅₀ 75.271.2 67.6 54.5 70 63 (wt %) TREF (90-105° C., 2.3 6.9 4.7 19.9 5.8 11.1wt %) Mn 52889 51517 47091 35979 46138 35691 Mw 100059 117526 102959186200 87748 89012 Mz 169597 635217 199260 1629317 144899 181182 Mw/Mn1.89 2.29 2.18 5.18 1.9 2.49 mole % of C6 8.2 9.3 7.3 5.8 7.1 6.8 wt %of C6 2.9 3.3 2 2 2.5 2.4 Comonomer 1-hexene 1-hexene 1-hexene 1-hexene1-hexene 1-hexene Comonomer normal normal normal partially normalreverse Profile reversed (GPC-FTIR) Peak Melting 109.2 99.4 115.1 121.8113.7 118.4 Temperature (° C.) % 37.4 35.5 41.5 48.9 41.2 44.1Crystallinity

As shown in FIGS. 5A and 5B, spheroidal catalysts 1A and 1B give rise tospheroidal polymer particle morphology respectively. Spheroidal catalyst2A also gives rise to highly spheroidal and uniform polymer particles asshown in FIG. 6A, while catalyst 2B, although providing polymerparticles with good morphology, gives a slightly less spheroidal polymerparticle (see FIG. 6B).

All of the inventive catalysts 1A, 1B, 2A, and 2B, give polymerparticles having much more uniform and more spheroidal morphology thando either of the comparative catalysts 4 or 5: compare and contrastFIGS. 5A-6B with FIGS. 7 and 8.

Thus the polymer particles produced using phosphinimine catalysts madeaccording to the present disclosure (catalysts 1A, 1B, and 2A, 2B, whichare supported on spheroidal magnesium chloride which does not havesignificant amounts of an electron donor compound present) are much morespheroidal and hence have much better morphology then the polymerparticles produced using comparative catalysts 4 and 5 (which aresupported on silica). Furthermore, the polymer particles produced in thepresent disclosure are spheroidal and have good morphology anduniformity, despite the absence of a pre-polymerization step. This marksan improvement over other catalyst systems which require an initialpre-polymerization step to obtain good polymer morphology.

INDUSTRIAL APPLICABILITY

The present disclosure is directed to the use of solid, spheroidalolefin polymerization catalysts for the polymerization of ethylene withat least one alpha-olefin comonomer. The catalyst polymerizes ethyleneoptionally with one or more alpha-olefins to give an ethylene(co)polymer having improved morphology and bulk density. Production ofpolyethylene copolymers having improved morphology and bulk density isdesirable in commercial scale gas phase polymerization processes such asthose which take place in fluidized bed polymerization reactors.

The invention claimed is:
 1. A method of making a spheroidal olefinpolymerization catalyst having a particle size distributioncharacterized by a Dm*/Dn of less than 3.0, wherein said methodcomprises: i) combining a dialkylmagnesium compound with a non-proticether, ii) combining the product of step i) with a source of chlorideanion, iii) treating the product of step ii) to substantially remove toprovide a MgCl₂ support containing less than about 2.5 wt. % of thenon-protic ether, iv) combining the product of step iii) with aphosphinimine catalyst and a cocatalyst.
 2. The method of claim 1wherein treating the product of step ii) to remove the non-protic ethercomprises heating the product of step ii).
 3. The method of claim 1wherein treating the product of step ii) to remove the non-protic ethercomprises adding an alkylaluminumchloride compound.
 4. The method ofclaim 1 wherein the phosphinimine catalyst has the formula: (L)(PI)MX₂,where M is Ti, Zr or Hf; PI is a phosphinimine ligand having the formulaR₃P═N—, where R is independently selected from the group consisting ofhydrogen, halogen, and C₁-C₂₀ hydrocarbyl; L is a ligand selected fromthe group consisting of cyclopentadienyl, substituted cyclopentadienyl,indenyl, substituted indenyl, fluorenyl, and substituted fluorenyl; andX is an activatable ligand.
 5. The method of claim 1 wherein thephosphinimine catalyst has the formula: (L)((t-Bu)₃P═N)TiX₂, where L isa cyclopentadienyl ligand, a substituted cyclopentadienyl ligand, anindenyl ligand, or a substituted indenyl ligand; and X is an activatableligand.
 6. The method of claim 1 wherein the phosphinimine catalyst hasthe formula: (L)((t-Bu)₃P═N)TiX₂, where L is a substitutedcyclopentadienyl ligand, or a substituted indenyl ligand; and X is anactivatable ligand.
 7. The method of claim 1 wherein the cocatalyst isselected from the group consisting of ionic activators,alkylaluminoxanes and mixtures thereof.